Even as a seasoned investor, it's one of my favorite ways to find houses.

(as for California and New york it seems)Our goal is to invest on rental properties (we can't flip from France) with very low expenses in a safe area.

As far as a time period that you should wait goes; most lender will require a 6 month "seasoning" period from the date you purchased your property.  

Below are some quick tips about cash out refi vs HELOC/LOCCash out Pros-tax free money-low interest rate-fixed monthly payments unless you choose a variable productCash out Cons-closing costs (couple thousand)HELOC/LOC Pros-tax free -its a line of credit, hence you can use pay back then use again-usually NO closing costs on residential Helocs; there will be closing costs on commericial LOCs-commericial LOC is very fast moving as far as getting funding and refinancing  (Makes it easy to rinse and repeat)HELOC/LOC Cons-higher interest rate-variable rates-monthly payments depend on amount borrowedHope this helps,CB

You can get in with a low down payment and good terms by living in the property.  

Or you could ask a seasoned investor you trust to help with ARV estimate and offer to JV in exchange for his / her help.Having properties priced lower than yours won't affect the price of yours if it is not comparable (comparing price of a 3/2 brick ranch to a 2/1 MH, for example).

--First and most importantly...generally speaking, when are peak rental seasons and how many weeks per year can a good mountain cabin be expected to rent in the area?  

Though the city needs a lot of work in terms of crime and school, there aren't too many small/mid size cities with the arts, food, nightlife, access to suburbs, lakes, wine region, etc. that Rochester has while having extremely low taxes. 

Both have great rental histories, are located in very good neighborhoods and very low vacancy.  

My assumption is I'll need to invest out of this area, as cap rates around Palo Alto are very low.