@Lou Palazzo
You are asking some great questions! I'd love to try and help answer some to the best of my ability. I'm an agent in Minneapolis.
1st. A lead you uncovered yourself. Very often these leads will have already assumed that on the buying side an agent will be used to purchase their home or this property. This means they have built in the buyers agent commission costs and plan to include that agent. They do this simply because of supply and demand. Why would a buyer agent bring their buyer if they were not going to be paid. They would pass and move onto the next property. That means even if you "found the lead" have your agent schedule the showing and walkthrough the property with you. Again, they can give their opinion and maybe it is a bad deal. Not every property not posted on MLS is a killer deal. ALWAYS... Buyer beware.
2nd. Even gaining more experience I would say use an agent. With that agent you receive their contacts and connections. As well, you have contact with their broker who could have 20+ years of industry experience. The Agents job is to make your life easier and less time intensive. All well run businesses delegate work and tasks, which cost money but saves you time. Why not do that with your own company or portfolio of investment properties?
3rd. If the seller does not have an agent A.K.A For Sale By Owner (FSBO) than often times your agent can write in the commission payout in the contract/offer. Many times this is not an issue with sellers because they will assume they are paying a buyers agent. From their perspective they don't want to use a seller's agent b/c of the addition 3.3% commission rate. If they refuse to pay a buyers agent, then you can pay the agent at closing and build that into your model or move onto the next possible deal.
I hope this helps!
Sam