Is this a normal and works as intended:
1. Terror at first month?
2. Unbalanced monsters like a dogs and hounds on a first month?
3. Enemy with laserguns at first month?
4. YOU WITH SNIPER RIFLES, LASERS, HEAVY ASSAULT MACHINEGUNS, RPG'S, CAWS, AT FIRST MONTH?
5. Sniper-like rifles less effectively like a sniper weapon(one-shot kill) than bombard, due to unworked 999% hitchance?
6. Almost half weapons worse than bombard?
7. Frustrating experience after pressing "ABOARD" button?
8. 90% of all weapons - trash?
9. What is the point of researching low-weapons, if you get at the beginning of the game stuff on a several tiers higher and examine them instead of wasting time for researching garbage?
10. Experience and hit/sight system?
Short answer, yes it's working as intended.
Long answer
1-4 are all sort of related. The missions are all pretty random so you can get most missions at any time, like the mutant pogroms (terror missions). If you can beat enemies carrying lasers, machine guns, rpg's, etc with your trusty muskets, handles, etc. then you'll get those as loot if you can manage to win. Bring body bags for the harder missions if you try.
5. really depends on the enemies you hit with snipers/bombs, everything has different armor levels and resistances vs piercing (sniper) and concussion (bombs). Terrain is a factor here too, different weapons are better suited to different terrains.
6. Bombs have always been pretty cool, not sure if they're better or worse, like the answer to 5, it depends on what you're bombing.
7. no idea what you're talking about here.
8. One mans trash is another mans treasure. As you start dealing with more enemies (and there's a lot of different enemies) you'll have to revisit some of the "trash" weapons.
9. A lot of research needs lower tech items researched before it unlocks, that being said I generally don't bother researching individual weapons very often unless I need something specific. I rely on prisoner interrogations and stuff like gun almanacs for all the weapon unlocks. Also, sometimes you need to have a weapon researched to be able to buy ammo for it on the black market.
10. exp is fine IMO, the LOS system is kind of flakey but you'll get used to it over time.