Litter box & sleeping arrangement troubles... HELP!!!

Hi!! I'm a first-time cat owner and my kitten Figaro is 7 weeks old. When he got here almost a week ago he seemed to be litter box trained because he used it right from the start and didn't go anywhere but there, though he wouldn't go by himself, he'd meow and we would need to take him to the litter box and wait for him to finish, or he'd just follow us. A few days later we noticed he had been going by himself, and he knows where his litter box is supposed to be because he stands there and meows when we move it. However, on his 5th night here, he peed on my bed twice while I was asleep, and the following night did the same but with another type of little present!!!

I know he knows how to use his box and knows exactly where it is, and it's clean and completely accessible, so could this be a sort of kitty "acting out" deal? Maybe it's the sleeping arrangement, because we haven't had this issue whatsoever by day. Before coming here, he was still living with his brothers and sisters, so I think he's used to sleeping with someone else's warmth. The first couple nights I tried putting his bed next to me in my bed, but he ended up sleeping curled up under my chin because he wouldn't tolerate being alone, and by the third night he finally slept in his bed, next to me. On the fourth night I left his bed on the floor by my bed, but when I fell asleep he was still roaming around the room and playing, and when I woke up he was sleeping under my bed, on the trundle bed mattress. Today they're bringing me his brother, who we'll be taking care of for a month or so, so I'm hoping they'll keep each other warm by night.

Any recommendations on sleeping arrangements? Should I leave the two in a room by themselves by night? Figaro cries so much when he's by himself and he's still so young, I'm not sure if that would be the best solution. Also, he takes tons of naps and sometimes isn't sleepy when I go to bed. I assume that's healthy and normal for a young kitten, but since he falls asleep after I do, he ends up sleeping in random places. Is it important that he learn to sleep in his own bed or is that inevitable cat behavior? 

Sorry, so many questions!!! If you have any suggestions or ideas regarding any of this, I'd really appreciate it!!!

A 6-week old kitten is really too young to be away from mum, and litter tray issues are more common with these babies.  When his brother arrives hopefully you can leave them togeather overnight and relatively confined - kittens this young are like small children, when they realise they need to go it's Right Now.  It is NOT any sort of 'acting out'. 

Kittens sleep a lot, that he wants to play when you are ready for bed is par for the course.  And about where they sleep - my cats very kindly let me share their bed.

OK, thanks!!! His brother arrived and at first he wasn't too pleased, but I'm sure he'll be happy to have company when we're out for a few hours. I agree that 6 weeks is too young, I intended to pick them up sometime after 8 or 9 weeks, but unfortunately their mother's owner didn't want to keep them longer I'll try confining them together by night as you suggested and see how it goes. Thanks again!!

Far too young to be away from his mum, to ensure he uses his litter tray he needs to be kept in a smaller area with a few litter trays, so there's always one around when he needs it.

Him not sleeping in his bed in no big deal, and not unusual for him to cuddle up with you. Crying when alone is completely normal, he should still be with his mum and littermates. He should be comforted when his brother arrives, but do expect him to be upset when the brother leaves again.

If you stick to a routine he should sleep better, we do a good 30 min play session followed by supper and bed at night-time and they all settle well.

Is it possible to keep his brother?  Cats tend to be much more content with a playmate and will bother you less.  Adopting a sibling ensures that they grow up together and will be much more likely to get along.  They learn a lot about how to play from eachother.  A cat taken too young from mom and siblings tend to have behavioral or biting problems.

I wish I could, we're quickly falling in love with the little guy, but unfortunately he already has a new owner, we're pretty much his temporary home until his owner moves to her new pet-friendly appartment building. But yes, we've definitely noticed that Figaro is happier, more active, and even sleeps better since his brother arrived. I'm thinking of looking for a second cat who could stay for good so that they can keep each other company. I know it's not the same as raising the two together from birth like it is with Oto, but I'm hoping if they're still young enough, they'd be able to adapt. Anyway, thanks for the input!!

Yep, it certainly is much easier to introduce kittens to each other than adult cats.  I'm sure it will go well, just try to select a kitten with similar personality and energy level.  That's great that his brother found a good home though.