Does MEPS pull your military medical records?

Oh yeah and if you want to be in the Army, you should get familiar and start practicing the Army values... Start with integrity.

Yes, but you would be surprised at how many waivers they approve.
On the other hand if you were barred from reenlistment, medically retired or put out for an injury then chances are you will never wear the uniform again, although a good war makes most all of these problems disappear and they will approve all waivers at that point. During the surge we had everything from convicted felons to soldiers that were awol for years just show up during the deployment as fillers for the units that just needed bodies to meet mission parameters so there's always a way if you are serious and have a great recruitment center.

They could find out things you never even knew so just be honest.

I was recently looking at transitioning from one service to another, and the thing that determined if they'd need to provide a full enlistment physical was whether there was any break in service.
I wouldn't see any reason they wouldn't check medical records though, but I'd ask the recruiter for the most relevant answer.

depends, if they're on file and SOP

I believe they have access to any federal health records including TRICARE and DoD health records. So yeah I be fairly certain they will have your military health records.