No featured developer or expert/master here, but a 30 year+ hobby programmer. So I chime in with my ideas.
1. If it is a hobby, why care? There are ways to get better at time management. And committing yourself to a plan: doesn't sound fun

2. Optimizing time. You need to have learned to do that and sometimes you learn along the way that there are other/better ways. It is hard to start over, but sometimes it is worth it!
3. True
4. Yeah! But look at your own work. You have managed to get a lot in and it made things better
5. It is better to make it for ' yourself ' first. Industry Breaking? Ehh.. it requires special skills like wizardry
6. When starting in Game Dev I would suggest to make a lot of games first. Don't put too much time in polish in the beginning
7. True. But look at 1 and 6

But it is nice to have at least a working thing from start to finish and not 100 games that have only a start
8. Don't compare yourself with others. You see only a small part of all the work/time it took them. Being critical is always good. Too much of anything isn't good.
Experience comes over time. Do what you like to do, no matter how much time it takes.
If you like what you are doing you are motivated and even on times where things don't go as fast as you want them to go it will help if you still enjoy the process.
Even if that means that you want to build an massive online multiplayer roleplaying game like WoW. But you have to be realistic about it.
Most Triple-A games have budgets for over millions of dollars and have at some point in time thousands of people working on them and then it takes them years to make it.
Calculate that to the number of hours (and given that most of them are experts in areas you aren't an expert in : triple the hours)
So to make something that big will require an entire life time. Well spend if you like everything about games and game design, but you should really get good at time management and committing to a plan (ha ha ha ha)