I played this game non-stop at launch.

The problem with the game was that at late game it started to get too easy. The crafting system seemed broken - I was able to craft dragon armor and other things to make me essentially invincible. It almost seemed like there was an exploit, all you had to do was find resources, make small things, and increase your skill. It seemed like the things you craft should be limited by your level so you don't become too powerful for the content in your area.

Also, in combat, you could keep drinking potions, so it really didn't matter how badly you were getting beaten on. Seems like they should have limited the number of potions you could drink in a short time span.

Did they make any significant changes to the crafting and combat systems that would make the game more enjoyable if I start over?

Are there any patches I should look for?

No, why would they? It is not an MMO and Bethesda stopped working on the game a while ago.

You should update to the latest patch, which is 1.9 when you start the game. There is a Legendary difficulty. Otherwise it's still the same.

Also, you should look into getting all 3 of the DLCs.

Patch 1.9 adds (as said above) the Legendary difficulty and making your skills 'legend'. This resets a skill tree, allowing you to level up a skill all over again. With that, has the level cap been lifted from level 81 and it's pretty much limitless. That's probably the only patch that has added some significant changes.

The Smithing skill was modified around patch 1.5 or so. It changed the way the skill levels. Previously it was based as a flat rate no matter the weapon or armor crafted. Now, it is based on a flat rate of 25 + item value. Essentially making it advance similar Alchemy.

If you are on PC, be sure to get all the unofficial patches. Though you have to download them separately since the arbitrary restrictions on the Steam Workshop prevents them from distributing it there.