I only go as far as enchanting, smithing and purchased/looted potions will get me.

I used to go all out with making alchemy enchantments to make better enchanting potions to make better alchemy enchantments, etcetera. I even used one of the black books in Solstheim to alternate between better enchanting, alchemy, and smithing. It just got to be such a grind and steamrolling the rest of the game diminishes the fun a bit.

I just cut out alchemy so I'm less OPed and don't grind nearly as much.

Cheating is very hard to define for me, because I don't have any iron-clad rules. It's something I sense intuitively.

There usually comes a point when I begin to feel uneasy about something I'm doing in a game. I begin to feel something I'm doing is wrong for me, in some way. When I get that feeling I know I'm rapidly approaching my own personal boundaries of cheating.

I have never considered improving gear to be cheating in any way. Most of my characters wear sub-standard armor and wield sub-standard weapons. None of them have ever enchanted anything. And several of them do no Alchemy.

My characters tend to be "gimped" in some way. They tend to have an advantage in one area and a disadvantage in another. So it usually balances out in my games.

To me, it sounds like the problem OP is reporting is more of being "high level" than of needing to "cheat" one's armor. It seems to me that the game goes "out of balance" at a certain point, when combat skills and perks are maxed out, and the scaled enemies you're facing require you to rely on high level gear rather than your character's skills.

Anything is legit if provided ingame, cheating means to profit by unlawful means, exploiting and hacking, finding a loophole etc.

I have a strict and simple rule for more fun, do not use more than one crafting skill with a character.
Crafting is nothing more than another difficulty modulation.

I don't think taking advantage of the synergy between the three crafting skills is cheating, but I do know that after doing it with one character, I've never done it again. It was shortly after the resto loop had been "discovered." That character went from fun to forgettable, due to how overpowered she was. I learned that nothing kills fun for me in ES games more than predictable success does. I literally cannot remember that character's name now.

Some of my characters don't craft at all. They still do well, and reach high levels. More of my characters tend to use two out of the three crafting skills, and one gets ignored, simply because that is what makes sense for the character. Even then, they don't necessarily invest heavily in the perk trees. Regarding smithing in particular, quite a few have used it just enough to learn Arcane Blacksmith, and then they are done. Anyway, that's how far I go with the crafting skills most of the time, and it works for me.

I have pretty strong feelings about what constitutes cheating in competitive and/or cooperative games. In a single player game, however, I just don't believe the term cheating can really be applied. There is no victim, per se, leaving only the player's enjoyment to suffer. For that reason, any action that causes me to enjoy the game less is avoided, while any that increases my enjoyment is sought out. In general, I don't make use of exploits in the system whereby synergetic effects push things into unbalanced territory. That said, if you enjoy it, then why not?

I can say with regard to the crafting skills, I almost never use them to their full potential alone and certainly not with them acting upon each other. For instance, I don't improve my weapons and armor except where I like the aesthetic of a piece and want it to be of similar effect as my relevant level would allow (eg. smithing an Iron Sword to do the same about of damage as an Ebony Sword beyond level 36). For this reason, I also don't improve equipment before selling it either. I might feel differently if the NPCs of the world likewise used their crafting skills to great effect, but as the player is the only individual in Skyrim capable of obtaining Legendary equipment it just feels uneven.

I don't feel that using in game abilities as cheating. It is when I use something "unintended" (which happens in almost every TES game), like restoration loop to get "unintended" results.

I often find myself wondering, when I read posters "brag" about how great they are playing easily on Legendary difficulty, if they "cheat."

I rarely use fortify crafting skills effects. The only times I use them is to make low tier gear viable, like fur armor or a steel shield

When it is easy to buy it. I find it makes more sense lorewise for a warrior to make their own armor, or for a witch hunter to use bound weapons. Just seems more likely to me.

No matter the inherent skills adopted by any given character I create, be that any one or combination of Alc/Ench/Smith, I only improve gear to the point it reaches Legendary and stop.

... that is IF they ever get improved to that point, in the first place.

I would say using the in-game skills intelligently isn't cheating. I max out my smithing and enchanting. I rarely bother with maxing alchemy but I do often level it. I just try to max the skills I use and thats pretty much it, I do some grinding in the game to try and max my skills (which for most I define as being able to take the 5 damage/armor/magic affecting perks, smithing and block I get to 100). I have yet to play a TES game that feels like natural levelling is the best way to go so the grind is just a necessary component to me. So to the OP I would say maxing out those crafting skills and using them intelligently for boosting stats isn't cheating at all. Cheating to me is console command type stuff.

Depends on what difficulty setting you're on. If you're playing on the hardest settings then getting the highest possible values is only natural. If you're on a lower setting, there's a point where those become a little too overkill.

I wouldn't call it cheating, but the eventual lack of stimulation from always packing a BFG with infinite ammo can affect the entertainment value of the session.

I agree with you partly, however I think there are certain points in the game where the enemies are very much overpowered. One instance I can think of is the first dungeon containing silver hand members. They are extremely hard at low levels and only seem to get harder at higher levels when this really should be a "training dungeon" considering it's one of the first missions for the companions who are the first guild you encounter in the main quest.

Forsworn have always gave me a lot of trouble too at any level. I find myself having to resort to cheap tactics such as hit and run by killing one forsworn then running, hiding, waiting until my health regenerates then heading back to kill one more which makes me feel a bit Undragonbornlike

Sorry I should have mentioned this. I always play on Adept difficulty.

Personally, anything that isn't "intended" feels like cheating to me. I'd never use restoration loop, or anything like that to improve my skills beyond what natural skills and first time enchanting/smithing can do.

To more directly answer your question about whether you can succeed at high levels without such grinding, then yes. As others stated they don't do it every time. It is true that unfortunately to be able to have any likelihood of actually defeating some of the tougher scaled enemies at your level as you progress, you have to have enough good equipment or skills to essentially allow you to easily defeat 90% of everything else with very little planning or effort.

I often limit enchanting and don't often mess around with alchemy as it is so tedious and you can still get pretty uber without maxing out crafting. Some of my characters just have to make sure they don't get squared up by ebony bow wielding deathlord.