My initial response would be a
Clubiona sp hard to say which as many look similar.
If you're after Id's please give sizes (excluding legs) if you can.
I've lightened and sharpened your image.
As for bites - just treat them with the same respect as you would a wasp or a bee. in most cases their bites shouldn't bother you - no UK native spider has a fatal or close to fatal bite (unless you have an allergic reaction, which its sounds like you might be), but relax it's not interested in you.
If in doubt just scoop it up with a glass or card and move it along - outside will do.