It will all depend on what your goals are.Ask them questions that will help you determine whether they have the value/knowledge that you'll need to get closer to your goals.

Hi, pre foreclosure in all of its permutations, before the bank sends Notice of Default (NOD) or efter which is state even county dependant but often starts a 4 week clock till the trustee auction are the 2nd most difficult deal scenario and IMHO only experienced investors should bother, the 1st most difficult deal scenario are bidding at the court house steps on lord only knows what is being auctioned off sometimes even 2nd mortgages, you need to do so much home work to attempt to reduce your risk at the court house steps...Pre foreclosure no one talks about these issues, always about the nice sounding stuff like "motivated seller" get a good deal etc etc both are usually not the case.- 95% of folks in pre or post NOD want to stay in their house, keep their house inspite of them 100% will loose the house at the auction. 

That said, depending on your business, you can definitely get creative with tax deductions for your RV or boat.One thought—it’s too bad you’re not considering the RV as your primary residence.

How much profit you make depends largely on your targeted clientele and your property management. 

It really depends on market demand and location.

The better option would be depending on your priorities.

I  Income:  The amount of property you can buy will be dependent on your Debt to Income ratio.  

Of course, with all things, the answers to all these matters will depend on the circumstances.California tends to have more laws on the books and requirements and restrictions that it can be a good idea to form a CA LLC for out of state property so that you as a CA resident are covered, and to try to have your contracts fall under the purview of CA courts.

While @Phillip Austin mentioned Raleigh is a higher returns its just very much a appreciation market, you will not find rentals that cashflow, so depending on your goals its a good or bad market.

For a rule of thumb, replacing a commercial boiler can range anywhere from $20k to $150k, depending on the size, age, and efficiency.