I'm prior service Army so take what I write from that perspective.
My advice in no particular order is
1. Get it in writing-every promise, get it in writing with multiple copies.
2. Encourage him to choose an MOS (job) that helps him acquire civilian world skills. While blowing shit up is great fun, there is little call for that in civilian life. If there is an MOS that aligns with his degree then that *might* be a good thing. As other people have already indicated, recruiters are paid to fill slots and are NOT to be considered your military career advisor as it's not your best interests which are their priority. Many will say any and everything to get you to sign. They will over promise and under delivers. Again, I can't stress this enough, get the promises in writing in contractual form and find out what they will do if the OCS slots are "not currently open" or some BS like that.
3. Absolutely go to OCS. Getting paid much more for way less BS is a good thing. NCO's and other enlisted will act like they are all that because they are enlisted. Appreciate them, treat them right ,and build a good rapport, but don't take any crap off them.
4. If your son is interested in a tech field, then absolutely consider Navy or Air Force. Air Force treats their personnel better, but all branches will move you around quite a bit (usually every 2 years) and that can be tough on a family, but the experiences are amazing.
5. If you have any other questions, please ask. I wish I had done more homework despite being proud of my service to my country.