friends list and shop

So the first think is a friends list. I cant remove friends ( I do not know if everyone has such a problem but my friend have this too) . Second one. when my friend and I buy a champ we didnt lose IP but we lose it xD like -> I have 6305 IP on my acc im going to shop and buy so its 6305 - 6300 = 5 right ? I buy him and what? on my acc was still 6305 IP but i cant buy another champ because i have 5 IP I don't know if it's well explained but i cant better :D