In another thread a modern port is mentioned that allows you to play Abuse on modern operating systems, without frame rate limits and other niceties.
That is probably the way to go if you want to enjoy this game nowadays.
But if you want to play it in Dosbox, the default experience might not be so great.
The main issue imho is the controls. Whose idea was it to use arrow keys for movement and mouse for aiming?? Idk about you, but I use both of those with my right hand. For this to work, I need two right hands! I don’t have two right hands!
Anyway, luckily Dosbox comes with a built-in keymapper. You can bring it up by pressing ctrl+F1. Simply click the arrow keys, choose “add bind” and press the wasd keys on your keyboard to add these to control the arrow keys.
Now you can play it with two hands!
As for the frame rate, I’ve heard people say it fluctuates wildly, but I’ve not really seen that. I think what might fix this is setting a fixed cycle count. I’m running it on auto at 45% and that seems to be ok, so that’s another thing you can try.