Thanks!
1. Sure it is difficult but as you can see on my YT let's play, perfectly beatable on Superhuman
Terror missions indeed can be a bitch, but not on low difficulties, where you don't run into risk of too many cyberdiscs/power armor to handle... You absolutely need dynamite and smoke grenades (dynamite->everything), and you need to take advantage of increased mobility (axe->power armor). If things get too hairy, do not shy from running away. You need to pay much more attention to strenghts and weaknesses of your weapons and soldiers than in vanilla. Losses are nigh-impossible to avoid. This is definitely not a casual mod, but I think it gives the player a fair chance. I've tried to avoid cheap tricks like convoluted maps or irrecoverable weapons.
Sadly, there is no connection between difficulty and the number/type of UFOs so it's quite irrelevant. The difficulty only influences the number of enemies that spawn and, to a lesser degree, their stats.
2. This is an engine thing. Only ranged weapons can target terrain, and I really don't want to make more melee weapons ranged. Besides, if I did so, you swords would eventually have the ability to smash through UFO walls