Right now we are in the learning and knowledge building phase but he (being more action-oriented) is ready to find places now.We're both excited but I think he is more short-term driven, while I am interested in long-term accumulation.

Equity accumulation through principle reduction. 

I would of accumulated ~$50K in interest, get ~$110K at time of refinance, help her building credit, and not have to worry about the house (too much).What are your honest thoughts?

I let all the cash flow accumulate into a fund.

We would be using the equity from our primary residence in the Bay Area that had accumulated equity thanks to the red hot market here.

. :-)I know some Pro members who have used this strategy to accumulate a big portfolio of rental houses in a short period of time.Personally, I don't use this strategy because my long term buy-and-hold are apartment complexes (I own a 133-unit apartment complex).

But I was able to accumulate over $1MM in the East Bay from literally nothing a few years ago.

s point, I would work on accumulating cash.

The 4plex would be perhaps the largest and most valuable property we could get other people to pay for in effect.We are leaning towards the 4plex, but also considering the extra cash it would tie up and if that cash put elsewhere could more than make up for the higher monthly payment , lower equity accumulation, lower tax savings of the duplex. 

The longer your stay here, the more you end up losing, and more important...you have lost time that you can't recover...like you can the lost cash you've accumulated thus far.