You should probably get a different binding, because that is only a 7 din, which doesn't give you any room to go up really. You don't need something great, a marker m 12 would be fine or a look px12 or nx12
Oh yeah then definitely. Originally I thought that it was your first year skiing anything, and even then a 7 din binding might not be enough. If you have skied before, I would recommend the look/rossignol/dynastar px12. It's a solid binding that would be good for you. Plus they aren't really expensive
On a K2 Bad Seed, for a 49kg guy? It'll be fine, chances are he'll be on some bigger, better skis in no time at all, no point getting a new binding in mean time.