I'm adding a new comment because this is probably the closest answer that I have so far as to what this bug is.

The many bugs are probably mirids, whilst the lice is a cat lice.

I say that because we have a bunch of stray cats that like those wooden benches and because a cat lice looks really similarly.

This would also explain the day light activity and their tendency to stick to clothing and not crawl around in my hair, because they are not human lice.

All in all, I'm still not sure that this is it. If any of you have any further suggestions (besides bed bugs ;) ) i'd love to hear them.

Thank you all for your help!