There are some things that you have good points on and bad points on.
1. Thorium isn't available when it should be.
2. Some essentials are overly difficult(but not overtly difficult) to obtain
3. There is no energy weapon that attacks air units.
1. You think that the game is supposed to be easier than what it's designed to be.
2. Turret rotation is fine, if you used the turrets correctly they would do their job and destroy the air units.
3. The plastainium (although annoying) is hard to make for a reason, it's a industial based game, make more power, power more pumps, and harvest like no tomorrow.
4. The customized loadout is designed to allow for replayability, it's so that you can take resourses from hard to maintain maps and send them to easier level so that you can relax and focus on converting what you need to convert.
5. The scatters are extremely useful, they are for air invasions, oh and have you heard of the ripple or hail? They're ground turrets, they're separate for a reason and there's a reason why it's long range.
6. The mend projector is a temporary fix, if it wasn't then just imagine how easy the game would be, it's purposely trying to force you out of the zone and it gets harder.
Unless you actually play the game, and think strategically about it, don't complain about being bad at it. If you like you can ask me for some tips, I've actually put effort in and would like to share my findings.