Moving out of state, moving closer to work, school or moving into a bigger home due to expanding family like "pregnant" and/or requiring additional rooms or larger GLA.If you purchase a 2-4 unit and try to purchase another 2-4 unit if they are not "Common" to the area you will have a hard time.

There is no problem with a NonQM wholelender or a broker to do a 5+ to 30 unit STR.It would be a DSCR loan and I love the Airdna report that can help get your loan to debt service.There are options of looking at rent rolls and or statements from Airbnb, Vrbo and so on.

Is there a certain neighborhood, owner occupied vs. not owner occupied, length of ownership, debt on property vs. no debt, etc.

Only sell if you have to, or you can move the money to another investment that can produce a better return.If you keep it, you'll have additional income for life.

The house is a 3b/2ba 1,895 sq ft home but an additional sunroom built in which brings sq ft up to 2,055 (based off tax records my agent found).

As far as I know, MLS access is only for dues paying licensed members, so unless you get licensed and pay probably $1000 or more a year, you won't be able to get direct access....and you'll also pay for some additional headaches. 

All thibgs being equal,, no agent can get you an additional $100k if comps are in the $550k range.  

I dont think you have enough equity to refi and consolidate the two. combining them puts you at over 96% LTV. cash-out will likely max you at 75% LTV of the $450k, so raising your rate on the bulk of the debt probably is not the move if you still have to bring in $100k to do so. is your 2nd going to balloon soon?

Although they do have homeowners that are consolidating debt, that isn't their primary customer.

However, not all of you need to take on the DEBT portion.