How often to corns, Have a poo and a wee, Whats 'Normal'..?
As often as you feed them.
He's been fed 1 pinkie every wedensday and saturday....?
How can i tell between 'poo' and 'spew' is there a Major difference? Poo will have yellow liquid with black poo and maybe some brown and white. Spew looks like you can still identify that it used to be a mouse, it will smell nastier than poo....you will know it's gross. Somtimes the poo was not completely digested either and you can see a little bit that isn't regular poo but that doesn't happen unless the snake was cold.
How suseptible(Spelling) are corns to dust/deoderant/aftershave etc?
Don't worry about it but don't go rubbing aftershave on your snake.
How often should i bath him, if at all? Bath him only if you want to to keep him clean for handling. I wouldn't wash him more than 3 times a month.
Should i move on to 2 pinkies every wedensday and saturday, or stick to what im doing now?
Two pinkies a week is just fine. Or if you want to increase growth speed you can alternat 2 pinkies at once and then 5 days later only one pinky and then 5 days later another 2 pinkies at once. But what you are doing currently is just fine too.
Hope this helps, and I would also suggest reading a couple different care sheets.
-----
2.2 Corns (2 striped and 1 okeetee and 1 blizzard)
1.1 Graybanded
2.1 Banana Cal Kings
1.1 Leopard Geckos (High yellow and Jungle)