Let's just say that QMC has onsite police and security, sniffer dogs and barbed wire around the perimeter. (Maybe not the sniffer dogs.) I felt far safer in Bristol than I felt at QMC.
I think you're over-thinking whether being in London would give you any advantage for getting work experience or making connections. It really wouldn't. The quality of the university that you attended would more than neutralise any geographical element. Besides, Bristol has many great law firms in the unlikely event that you would be doing work experience during term time, and during holidays you would just go to wherever you can get work experience in order to perform it.
Yes, Bristol is a busy and exciting city. There won't be the slightest risk of you confusing it with North Wales.