I  have had unsolicited offers of 150k, so I am in a good position if I just simply cashed out. 

As you buy properties and built more equity, you will be in a position to need them.  

.- My payments (PITI + HOA) total $700/mo, but I rent the property for $1,200, so it has $500/mo in positive cashflow.

If you have equity in this property you have negative cash flow not positive. 

There's a cool meetup the 2nd Saturday of every month that might be perfect....no sales, just a bunch of people in similar positions as you trying to figure it all out and sharing resources.Have you started looking for properties to house-hack yet?

As long as the property value go up, and you can maintain positive cashflow, you are okay.Overall, higher risk, and you will need an exit strategy when market values go south.Terry

I'm trying to have all of my factors in order before I make an offer so that I present one that would benefit both myself and the seller without putting myself in a bad start position on my investing journey.

Owning one property with 100/month positive cash flow can be very draining if it is necessary to deal with tenant issues.

(this is not very likely because of your lack of experience and high LTV) This lender would be in a 2nd lien position and not very secure if you fail. 

Depends on various factors.But yes, if you have a rental property that is producing net passive income, you can invest on the property that has high appreciation potential but less cash flow.That way you can use the tax loss ( it might still have positive cash flow) to offset other passive income.This way, you can also tap into the equity of the appreciated house in few years and still enjoy the tax losses.