Warranty questions and help me choose LAPTOP!

I was wondering specifically how warranty works? I am planning to buy a laptop on craigslist and I'm don't know much about plans,cover and warranty regarding them.

Does warranty transfer? If one were to buy from another private owner, how would you prove that you have legal ownership on it to register warranty in your name? Or is that not how it works?

If the laptop were to malfunction or be damaged after I obtained it, would that be considered accidental damage or would that be covered under regular warranty?

How does warranty for RAM and SSD work? If the owner has receipts for it, how am I able to get warranty on them if I were to buy them?

I know that you can check warranty status (for toshiba) on their website with the serial and model number.

And which of the 2 should i buy?

Toshiba R835
First
Intel Core i5-2435M
R835-P83
Brand new
Full one year warranty
8GB ram DDR
120gb SSD OCZ Agility 3
Asking price :$650 My offer price: $625-630
Second
Intel Core i5-2435M
R835 ( not sure what model)
Used, have not seen it in person yet, 1 year old
Warranty unkown
6gb ddr3
640gb HDD
Basically same features as the first one except the upgrades
Asking price : $425 My offer price: $380-400