Trust me, the house is only pretty at Christmas. It's a drab, soulless, cramped little abode the rest of the year. As far as plants go, not really. I used to keep cacti in my windowsills, but they all eventually died. Plants are strictly for the backyard now.
No other pets, I could easily become someone that has even more cats, though. I have a severe soft spot for stray animals and, well, cats just complement my personality. I don't dislike dogs (although I have a phobia of large dogs), I guess I just value independence over loyalty.
15 is the upper end of the average lifespan, 20 is statistically improbable. Lucky cat. My old cat just has a defeated look in his eyes, his legs and neck are also becoming scrawny while his chest becomes larger as he has congestive heart failure. It's a sad thing to behold, as he's been my constant companion since I was 8.
This particular cat has always been very large but not necessarily fat; just in body structure he's abnormally sturdy and big, bigger than some dog breeds. This was part of his downfall as his greater mass wore him out more quickly...same principle as 2.3+ meter tall people dying early because their hearts can't effectively circulate blood through their body, I suppose.
Fat cats are indeed quite huggable, though. My youngest cat is quite fat, though not from overfeeding. Female cats have a high probability of permanently gaining a lot of weight after being spayed, which happened to this one. She's squishy and just a pleasure to hold and cuddle.
About selling, it's really just games and dvds. Find something at a flea market, pawn shop, or yard sale for an abnormally low price, buy it, hope to sell it for more than what I paid. It's not always fun but I've managed to sustain my hobbies after having no income for a year and a half.