I'll answer all your concerns bro:
1. Personally I'm not a big fan of diesel. And compared to the 3UZ, the 1HZ is a lot older. And then there's that love for V8 I have
2. It's not bolt-on, there have been alterations made, but the person who is performing this swap is reliable and has done the same in the past more than once. I personally know someone who had the same engine swapped in the same car and he hasn't had any problems so far. Other than that, 1UZ swaps are even more common. 1UZ and 3UZ share similar dimentions in terms of mounts etc.
3.I hope so! Again, I know a few people who have done the same. I'll keep this thread updated as and when there are new advancements. You'll see that I already have a brake and suspension upgrade in mind.