@ZZ:
Ad.1. Suicide. I removed most of my health with a help of a fellow aliens, then aimed RPG at a wall at point blank distance (I did not want to spend too much time because of lurking crash bug). I could not access Main Tower level 7 (as seen on screenshot), so i decided to take a break.
Ad.2. I cleared almost all towers on the first level - without Main and those parts of the levels that were inaccessible. After it I ascended mainly through Military and Security (with a short excursions to a Medical and Storage for Colt and Shotgun ammo and medpacks when needed .
And yeah, I am quite surprised to look at the amount of turns of yours o.o .
I believe the most funny areas are the Military and Security (and yet they are the most dangerous ones), thats why I usually stick to them when I play.
Ad.3. After previous games I noticed that some of Heavy Weapons show up pretty early (like RPG on the level 1), so thats why I decided to try it out.
It was my first time "playing" (rather testing) this class. I maxed Heavey Weapons around level 4 or 5 and walked with Plastisteel and Smartgun :) .
The best of class is that you are not limited when you need to change the armor - on one level you can walk with a Plasstisteel, on the other one with a Radiation Suit.
I was a bit surprised to find Power Armor, though. I think in the future version such armor (that allows you to have the extra armor AND HW capability) should be much more rare.
@screenshot:
I have found Pistol ammo, Medipacks, Smartgun ammo, Power Armor (and other stuff) in walls pretty often. Sometimes they were on a doors - and opening a door allowed me to get the item then.