Well, neither one is particularly great, but, personally, I'd take the Ruger over the Kel-Tec anyday. As for the Crimson Trace laser.. couldn't tell you. It's really a useless accessory.
Neither. "Better" depends on what you think, not someone else.
You will have to contact Ruger
There are laser sights for almost any handun. Try Crimson Trace.
350 USD
Both are fine weapons. What will make it "better" for you is subjective. If you want an opinion, I personally would go with the Ruger because it's caliber is .45acp, plus, Ruger has a reputation for building their weapons like tanks.
$250-$400, depending on condition and finish.
It hasn't been since at least 2003
You can request an owner's manual from Ruger. You can go to a gunsmith and ask for help also.
For a definitive answer, you will need to check with Ruger customer service. You can do so through their website.
It all depends on the model, caliber and condition of the Ruger. If I asked what is the price of a used Chevy you would probably ask. Which one, how old, what condition, Which engine. How many miles? It's the same with a used Ruger.
Its not a bad trade, depends on if you each want the other gun, I'd say whomever is getting the ke-tec is getting a better deal.
Part failure/out of spec. Get it to a qualified gun smith ASAP.