He just sounds like a scared new baby who is settling in
Their personalities do vary and also their behaviour can be different depending on their early life experiences. If he has been roughly handled or dropped before you got him he may be more nervous. I don't think it's aggression so much as fear. Give him some time and maybe a few more days to settle in before starting taming. Put his food and water out when he's asleep for a few days. Some hamsters do run at a hand in their cage initially if they feel scared, and he may be completely different out of the cage. I would suggest when it comes to starting taming you get him out of the cage and into a playpen or dry bathtub, by letting him walk into a tube (or into his ball if it will fit in the cage) and lifting him out that way so he can't see hands as such. Then time and patience. use an old toothbrush to stroke him initially while he's in the playpen/bathtub if you're worried he might try and bite then when you and he get used to it, move on to using a finger and gently put a hand under him and lift him a cm or two but let him walk off.
I sometimes think these very scared hamsters are the ones who really bond with you and like cuddles, once they are tame, but it can take some time and patience.
The pooping everywhere is partly nerves in my experience, and partly being young - they get into better habits when they get older. But i wouldn't keep cleaning out the poops - spot clean a bit if they really start taking over, but they are not smellyand dirty and they sometimes hoard them or eat them for extra vitamins (which is normal). They're just like little black hard seeds.
As he is quite nervy I would not clean anything for at least two weeks and then just spot clean mostly and avoid doing big cage cleanouts - you can do a bit one week, the wheel another week etc. If you use a litter tray and spot clean and have enough depth of substrate, you can easily leave it 2 or 3 months without doing a substrate change. If you put the litter tray in his pee corner, with chinchilla sand in it, he will probably use it and then you can just empty that every 5 days or so andthe rest of the cage stays quite clean.