No, that guy is just a loser and a freshman simp. Where does he get the money for the van? He just can't interact properly with girls and his only option is stalking. Just a creepy guy. But he is not the only stalker of Riona and this is clear at the end of Ep8. The van belongs to someone else.
Quinn is not small. She sells drugs on campus, that's dozens of clients. She is involved in a large drug business run by more serious criminals from a gang with which she is related by blood. Through Quinn, the police/feds can reach out to the mobsters who run this drug ring in the city.
In any case, for the amount of drugs that she sells, she can face a long prison term. Ten years or more.
Somehow I doubt DPC wants to transform "Being a DIK" into "The Wire" or "Breaking Bad," so not sure we'll really get too deep into any of this, but I want to try and inject some realistic legal perspective into this debate:
The DEA is unlikely to be interested in Quinn or any drug dealing at B&R unless Quinn's organization has a direct cartel connection or some link to a much larger narcotics distribution and/or manufacturing operation. Local police would certainly be interested, though. A proper investigation would require setting up surveillance (from vans and UCs (undercover officers), for example) to learn details on all the dealers involved--not just Quinn, but any other people who sell (including Riona). The police will observe for weeks and months to understand the operation in as much detail as possible and gather evidence. The prosecutor guiding the police investigation will instruct them on what evidence they need to indict as much of the operation as possible, particularly any "big fish." Once the prosecutor believes they have enough evidence, the police will swoop in and make a ton of arrests. All the dealers, including Quinn and Riona, will be collared and would almost certainly see some jail time, if convicted. If Quinn has a lot of inside knowledge about the drug organization above her she could cooperate with authorities in the hopes of reducing her sentence.
I'm not sure Quinn would be viewed as a minor player in all this. Even if the volume of drugs is relatively small, remember that she is also a madam (she runs a prostitution ring), which in almost all US jurisdictions is illegal. If her drug ring also runs her prostitution ring and if Stephen Burke oversees both in some way, then suddenly it's a huge conspiracy. Let's just say that Riona is right to feel worried.
