It only matters if you're a criminal. He can do whatever he wants as long as it's not domestic assault. That was a recent change put in to protect you. If he has been convicted of domestic assault, he cannot sponsor you.
That's why he has to have a criminal background check too. You on the other hand better have a spotless record.
Obviously, do ask a lawyer and over at
www.immigrate2us.net, most of them have gone through the I-130 process for marriage and would know.
I'm fairly certain he could have a murder on his record and still sponsor you as long as it wasn't domestic assault or a previous wife he killed. Just make sure
your record is nice and clean.
Would your case be scrutinized by USCIS a little more closely because of his adult record ? Maybe, I really don't know.
Also, I wouldn't worry too much about the juvenile stuff if they're sealed. Juvenile records are sealed for most stuff but I don't know if it holds true for really serious stuff.