Shy Foster Cat Clawing Bathroom Door

Hey all, yesterday I picked up a shy, ten-year-old foster cat, Max, who was not doing well in his previous foster home. It was a cat house with multiple cats, and he was definitely near the bottom of the cat social ladder and losing weight. I have fostered a feral kitten before, so am attempting to follow the same steps; he's in my small bathroom with everything he needs plus some toys and a scratching post I just put in. He hid behind my toilet yesterday for a good long while until I coaxed him out with canned food. Eventually, he sat in my lap and snuggled next to me on the floor mat. This was completely unexpected because he tended to hide a lot at his old foster home except when his foster mom brought in canned food.

Anyway, last night he was scratching on my door jamb -which jolts the door in its socket and is loud- and meowing. He was clawing like he was trying to get out, rather than mark. I live in an apartment complex and am always worried about waking up neighbors. I ignored him -it was intermittent- and finally went to sleep. This morning he's doing some more of the same. I've put a cloth bag on the inside door handle to try and make it harder to scratch, and propped a chair against the door on the outside to stop it jolting. All of this works somewhat. I will be getting some double-sided tape for the door jamb today.

The reason I can't let him out of the bathroom yet: Luna, my resident cat. She hisses whenever she sees him through the door. Luna did this with my former foster kitten (Theo) as well, but through lots of baby-gate exposure, I was able to let them be together for supervised playtime and she handled it well at that point, except when he got to constantly tackling her. Then she got irritated, but tried to get away rather than dominate him. 

I thought about letting Max into the bedroom today and keeping Luna in the rest of the apartment, but I worry then that his escape attempts will be even worse at night...

Any advice would be greatly appreciated! Thanks in advance!

I hope you have a quieter night tonight!  I think the double sided tape is a good idea.  Also blocking the door a bit.  I have heard of using felt pads to help doors not rattle like that.  They should be easy enough to remove if you are in a rental.  Ignoring him when he is doing it is usually the way to go.  If he is after attention; then even negative attention will just spur him on.  

That's what I thought. It's been better the last couple of days, whether because I'm blocking the door somewhat so it doesn't rattle or because he's lessening his attempts, I don't know. I also put a shirt in with him that I've slept in (so it has my scent on it).

Recently though, he's started bitting and clawing me when I pet him. He's very lovey-dovey, rubbing his head on my hand and legs, kneading the floor, then all of a sudden he'll snag my hand. It happens so fast but I think sometimes it's when I'm pulling away (I've heard of some cats doing this as a "don't stop" command but it seems more aggressive than that) and other times it happens when I'm just petting and he pulls back and nails me. I've just been getting up and ignoring him for a bit. Does that sound like aggression? Overstimulation? I'm trying to watch his tail before it happens but I'm too busy worrying about the pointy end. After it happens, his tail is moving, somewhere in between lashing and twitching and he seems... sullen. Then in a little bit he's back to normal, loving and rubbing his head on me. Is it possible he's just expressing frustration at such a small space? I'm hoping to start site swapping him and my resident cat between my bedroom and living room this coming Monday...

It could be over stimulation, improper socialization or something as simple as having been taken from his mother and litter mates when he was too young to learn "manners". It's hard to know when it comes to ones with unknown backgrounds.  

Would the best way to deal with it be to leave the room? Just not interact with him for a bit? I know they don't understand punishment (I read through the "Do's and Don'ts of Behavior Modification article) but I'm not sure how else to deal with it. He seems sullen afterward so he may calm down in that case but is there a way to try and fix this? I'm hoping as he gets more space and more familiar with everything this will stop happening...