Any question answered...

this is the dent i was on about yesterday

it's in the middle of the top tube, and in the bottom pic it's the bit missing on the right hand side

how bad is this if I want to use it off road? I'm pretty sure its just from carelessly swinging handlebars

I say you'll be fine. I've ridden on worse and seen worse but then it's still down to how you feel in riding it. There's no point going off what someone has said on the internet, if you don't feel happy with it then don't ride it.