Fine, if you know what you're doing. I hope you have a suitable level of
encryption and MAC address filtering in use to stop all and sundry from
gatecrashing your network?

Yes. But more importantly, I regard the wireless network to be insecure, so
all the machines have firewalls as well. If you regard the wireless network
itself as no more secure than the internet, then you can't go far wrong.

But, IIRC, the OP had only one computer - which probably isn't readily
portable - in which case, I certainly wouldn't regard wireless as an
obvious - or even suitable - solution.

I see no problem. It doesn't even appear to be his own house, so a solution
that (a) causes less damage and (b) is more portable in the event of moving
out may be appropriate. The amount of time or money to conceal cables may be
a very real issue in some cases. On the other hand, some people don't mind
surface mounted cables ruining the skirting boards.

Christian.