We currently have 2 pc's connected to it, one of them downstairs is next to the router and is connected to port 1 via a cable to the network card, and is only used by the kids to look at childrens sites, nickleodeon, cbbc etc. The 2nd pc is upstairs and connects wirelessly with an adapter. This pc is used by me on sites like ebay and internet banking. I often have problems with weak signals etc and not being able to connect at all.
would it be better for me to conect straight to the router using my network card, and let the pc down stairs connect wirelessly as this pc only gets used after school and weekends.
I would say yes - not only for the reasons you give, but because hard wired (connected by cable) is far far safer for internet banking and so on than wireless.
I would offer a simple 'yes' to this as well. I don't know if you're aware, but the closer your router is to the actual BT phone point, the better (and quicker) your connections work.
I'm not a fan of wireless at all. Even with security, it is known to have some problems. We have three computers in the vicarage, with one being on a cable that's 80 metres away from the router. Always, it is the slowest in downloads and response.