you can enable yourself to always be the host in options to prevent that (from the mission select screen)Only complaint so far is that the match restarts if the host leaves.
My first game restarted twice at about 3/4 of the way through because of that.
Pressing "L" while in the inn will open server browser, nice to see what kind of stuff is available.
It gets pretty good if you have a swarm to position in between yourself and the gunner also. With a shield you can block the rattling for 5ish seconds also, by which time its easy to break LoSIt destroys everyone it is targeting, just charge it from an angle when not targeting you and use charge attacks when behind it.
there is no really overpowering gear, most of the stats are relatively minor, devs have stated they don't want power to depend on gear more then on skillTrinkets are meh. I found two so far (level 12). One is "take less damage from gunner rats" and the other one is "40% more health while knocked down". As long as there are no regeneration or damage/attack speed trinkets, they're very specific.
Also, I just grouped with a dwarf who had a crossbow that shot about as fast as the swift bow of the elf (so like twice a second). He also seemed to have unlimited ammo and one shot everything but the rat ogre. Cheat or well rolled orange weapon? If its intentional, this kind of gear seems required for the higher difficulties. He pretty much soloed Nightmare with 4 times the damage of the second place guy.
that being said, the difference between a weapon that can 1-shot trash on a given difficulty and a weapon that doesn't is huge, besides that the other affixes are small benefits
chance to gain ammo on kill / chance to gain attack speed on kill / 3rd affix would make a crossbow something like you describe
ps. In the horn of magnus mission, you can hide under the horn to kinda skill the finale, just take out gas & hookrats asap, other rats won't be able to get to you