If you look around, there are other similar MLS front end sites, but regarding "...other site that allows keyword search of MLS listings..." you will need a broker with MLS access (e.g. a Realtor) to search the broker only comments section.

The lawsuit, which alleged that the turf state laws harmed consumers by preventing access to the national market for commercial real estate brokerage and depressing real estate prices, was filed by a group of consumers, real estate brokers with Marcus & Millichap Real Estate Investment Services, a national commercial real estate services firm based in Encino, Calif. leading the suit.

There are those whom will take your money in exchange for some "service" or "access" to deals, knowledge, etc. 

I have access to some financing, but am looking to be debt free by flipping houses in the next five to ten years.

Create an address list and then in many cases you can directly access the tax records directly from that site (Zillow/Trulia/etc).

trying to create a platform that addresses the pain points of both renters and owners.

You may want to have someone with access to the MLS pull comps and get you an actual somwhat reliable value estimate than make critical investment decisions based on what zillow says.

Upper level built 1968, basement built 1992. 3 bed/2 bath.16 acre/1256 sqft Great view over BremertonNew laminate flooring in kitchen and entry waysNew tile flooring in upper level bathroomsPropane fireplace on both floorsBackyard deck on upper level Access to outside from basementAttached shedThe driveway is shared with another home so you are only able to fit 2 cars at most, but one will block the other.

Members and limited partners subject to charging liens have used varying means to access cash from their LLC or partnership entity to maintain a normal lifestyle.

If you don't have access already, you can shoot me a PM and I look up comps on the MLS and get an idea if there are rehabs that are drawing the numbers up in the $100K territory.