Well no-one can guarantee you anything. If Riot will be stubborn enough they can even check every suspicious account manually and find some clues and reasons to ban.
But to tell the truth - they haven't banned anyone for 1 year. I think only persons which made more than 250 risk to get banned. So with 10 refs you shouldn't even bother your mind... Btw. Riot never banned any1 in game for RAF abusing. They just ban from RAF.
About 10 Referrals check my sign.