Cros15, there are several things I can think of that might help out in your situation.
Don't feed milk, especially if it's cow's milk. His digestive system needs to switch over to obligate carnivore mode. If you absolutely must give him a dairy treat, a piece of cheese the size of a pea or bean will be fine; up to a level tablespoon of plain, unsweetened yogurt would be fine, too. And for now, no table scraps, either.
Regulating his diet properly will soon result in firm poop, not anything runny; it will become more firm and more difficult for it to stick to him. You may have best results with all dry food for his diet, with only a tablespoon or so of wet food at night, as a treat before bedtime. Check the quality of food he's getting, too; higher quality food usually results in less poop. At least 2 or 3 of the first ingredients should be meat (not by-products or digest), and no more than 1 or 2 grains should be in the first 5 ingredients.
I'd not use newspaper at the bottom of the litter. I'd use the largest litter pan you can find, though; he'll grow into it. (I use a concrete mixing tray.) And you'll want to scoop at least once a day; only put an inch or so of litter in the bottom, though, and put a little in to replace it each time you scoop. Once you're confident he's no longer stepping in his mess, you can start making the litter a bit deeper.
JCat has it correct; you're away all day, kitty's in a smallish boring room... kitty decides to nap the day away. You get home, and all hell breaks loose. Of course!! Kitty's excited to have his only playmate back at home!
When you arrive home, let kitty out and devote about 10 minutes to saying hi, petting him, tossing a toy several times so he can race across the room and run out some of his excited energy. (A tightly crumpled piece of writing paper does nicely for this exercise.) About an hour before bedtime, go ahead with another brief play session, maybe 10-15 minutes. Then let him wind down a bit. Right before bed, feed a tablespoon of wet food. (A full tummy helps encourage sleep.)
As far as the mess and allergies are concerned, there are several good approaches to take.
First, don't play with him with your hands - at all. Use your hand to hold a stick or wand with a toy at the end (on a stick or tied on with a string). Use your hands for tossing a toy or a treat. But it's really crucial to not allow him to play with your hands like a toy.
Second, if he scratches you, be sure to clean the scratch thoroughly with soap & water immediately, while still bleeding. Dab on a little triple antibiotic ointment when you're done.
Third, both to help with allergies and to help with mess, if he steps in his poop, as soon as he's done in the litterbox, stop & bathe him. (Make sure you have lots of bath towels for this task; a second-hand clothing store may have some. At his age, hand towels are plenty big enough.) I find it easiest to bathe my kitties using a tiny amount of simple human shampoo in the kitchen sink (which has a sprayer attachment). No water standing in the sink, and nothing but warm water gently sprayed over the kitty. He should have all 4 paws on the bottom of the sink; you can restrain him by the scruff if necessary, but if you do so, make sure all 4 are on the bottom of the sink.
Immediately following a thorough rinse, scoop him up in a towel, grab one more towel, and find your favorite comfy spot to sit. Cuddle with him, gently massaging him with the towel, and rubbing his forehead directionally from the upper nose toward the top of his head. Tell him what a good kitty he was (even if he was a terror). Swap out for the second towel once the first towel is a bit damp. Continue until he's very dry, give him a cat treat or two while he's still in the towel, then set him down.
Cats can actually learn to look forward to regular bathing, provided it's immediately followed with enough positive reinforcement. More than that, regular bathing (say every two weeks) will dramatically cut down on shedding and allergens. I have a friend who adopted 3 kittens from me; she bathes them all every other week, and they actually look forward to it! They get jealous if only one cat gets bathed that night (I'm not kidding). The friend has asthma, and has absolutely no allergy problems with her cats.
Reducing other allergens can also help. Hardwood floors with area rugs instead of wall-to-wall carpeting, blinds instead of drapes, a dust-mite-proof mattress cover and pillow covers... they all help.
And please try to be patient. Your kitty has lots of energy and no other playmates. If he were in the wild, he'd be wearing himself out several times a day with his littermates. I recommend a Cat Dancer toy if you really want to wear him out; it's inexpensive and lots of fun. Try not to compare him to other kitties you've had; he may not become cuddly and lap-seeking ever. Or at least not until he's grown through some of his kittenhood.
Good luck! He sounds adorable; I'd love to see a photo!
