With your trackpad issue, get an external mouse. Windows (or the trackpad driver) should have an option to disable trackpad when an external mouse is in use.
Might as well get a desktop if you want to be chained to a desk with an external mouse. Kind of defeats that whole "laptop" idea. My laptop rarely sees an good surface to use an external mouse on.
Seriously, not a bad idea for the times you are at a desk with it. My wife has had touchpad issues with her last 2 laptops, in fact hers is being replaced as we speak. Seems to be the latest big issue with laptops these days.
As for extended warranties, Staples sucks for laptop warranties. Always had bought from The Source and had good service. As noted above, for laptops batteries never make it 3 years so an extended warranty that includes batteries is a good deal if price is right. 2 laptops, both needed new batteries in last year of warranty. (Side note, if your battery has issues in 1st year, deal direct with manufacturer. That way your one time battery replacement of extended warranty will not be used.) In fact The source gave me a larger capacity battery on one of them as the original was not available in a timely fashion. We bought her last laptop from Staples as it was a super deal to purchase. Warranty we were told was same as The Source. Difference is that they kept the laptop for a month (less than a year old) and sent it back with a new issue, the touchpad.
As for TVs, my wife bought me an HDTV when they first came out, spent over 2 grand. I would not have done it, but it was a nice present. She got extended warranty on both TV and HD DVD player, it was a package deal. BlueRay won out over HD DVD format so player was scrapped before warranty was up. TV had no issues until about a year after extended warranty expired. Samsung had bad caps in the power supplies and i fixed it myself for $4 in parts. But the extended warranty was all profit for the Brick in this case. We bought all new energy efficient appliances and did not get warranty, they all had no issues.
So an extended warranty on laptops and used cars may be a good deal if you read the fine print and pay a decent price. anything else, forget it.