Second, currently i have a cheap USB wireless adapter, capable of my Internet speed. http://www.speedtest.net/result/2502599146.png (this what i get on my laptop right know)
Funny thing is, i pay for 35down and 25 up with 15 ping and get actually 45down 35up 13ping (when using cable, not wireless)
So my question is, should I take my time drilling holes in walls and moving ethernet through the living room and my room?
Or buy a better wireless adapter? if so what kind (USB or PCI etc.)
Your build should run Ultra settings as long as you don't use the AA Deferred and just stick with AA Post.
As far as networking, a game doesn't use a lot of internet bandwidth. I was using the Comcast "economy" speed at 1.5Mbps down and 768Kbps up and never had a single issue with BF3 or any other game. Lag is your biggest enemy. (aka, response time or ping) When you use wireless the Ethernet data packets are encapsulated into a wireless packets with the addition of whatever wireless encryption you are using. All this takes time and makes the packets larger with non-data data (if that makes sense to you) so it slows down your speed a little bit and adds latency. That is why your speeds are typically slower with wireless. The better your wireless equipment is, the better it is at doing this. In reality, as long as you have a strong wireless signal the added latency isn't going to add much, especially when you are connecting to servers hundreds or thousands of miles away that you are passing through countless routers to get to.
I typically try and connect wired whenever possible, but if you have to go wireless your biggest concern is get the strongest signal possible.