1. I, personally, think the voiced MC will be one of the BEST decisions Bethesda has ever made. You will still be able to select the tone of his/her responses - snarky, nice/helpful, mean/angry, etc. So, you can play the evil guy if you want to. Or the good guy. Or the guy who is a selfish jerk and just wants to know how many caps they get - screw the morality of it all.
2. The desolation will be there. Haven't you seen some of the concept art of the decaying ships, the dank marsh, etc? And, of course, we have yet to see what the Glowing Sea looks like. Even with vegetation returning, the world is still a pretty crummy place. And, of course, there are the Rad Storms. They can really mess up your day.
3. I LOVE how Bethesda has rolled skills into perks and attributes, and made it more streamlined, without limiting it. In Fallout 3, if you had Lockpicking at 25, you could open Very Easy and Easy locks. If you had it at 49, you could open Very Easy and Easy lock. What was the point of those 24 points?? They didn't make it any easier to open Easy and Very Easy locks. You didn't get a chance at opening Average locks. You had to wait until 50 to open Average locks. And then, everything from 51 to 74 was basically pointless beyond working to 75 to open the next level of locks. Same thing for Hacking. It was basically a perk system, it just wasn't called a perk system and didn't look like a perk system.
4. Skyrim is a different game. Sure, Bethesda made it, and yes, there will be bugs in Fallout 4 - bugs are inevitable. No piece of software, of this complexity, is ever made, by anyone, without bugs. Now, the best a company can do is learn from their previous experiences and try to improve. Not every bug will be patched. After a certain point, it just isn't cost-effective. Especially depending on the number of people it impacts, how game-breaking it is, and how long the game has been out. Fixing a bug isn't just fix the bug. You have to fix the bug, te3st the fix, see what the fix does to other parts of the game - does it break anything else? If so, how do you fix that? What does that fix break? And so forth. It's not like slapping a patch on a leaky tire.
Game companies have priorities for bugs and the completely game-breaking ones usually get fixed first (especially if they impact a lot of people). But even if a bug is fairly prominent, after a while, the company needs to move on to other projects. That's the way of the market. That's capitalism. Unless there is some sort of monetary reason or law that forces them to continue putting out patches, eventually, they will move on.
In the end, it's up to you to decide if/when you will buy Fallout 4. If you do, I hope you enjoy it! Based on what I have seen, and my past experience with other Bethesda games, I know I will. And if there are unpatched bugs, I know the mod community will do their best to help out. And for that, I am very appreciative.