While Redfin isn’t the most reliable source for estimating the values it indicates that I have about 400k in equity.

If there are any specific tips specifically trying to rent by the room house hack in a college, like things to look for in the house, how to estimate the correct rent, or anything similar to that i'd really appreciate the advice. 

I would also increase your underwriting rehab estimate number by 15-20% since most renovations go over budget.

Also what would you estimate for architect fee for 1 acre lot with utilities on-site and for 8k to 9k sft retail strip.  

Before using such a program get your own estimates.   

They have almost 6 months worth of rent in savings, but their house they are selling looks like it is paid for, and estimated at $450-$500k value (redfin and the county appraisal).

I do not have my numbers as well organized as @Greg Scott but my estimate is upper 20% annual return on average.The 3 i am currently invested in, one seems likely to produce an outstanding return (High risk, high reward), one is conservative and is performing to projections, and one i have significant concerns about but has not had a capital call.  

The rehab estimate seems very low and the ARV seems really high in my opinion, just based on a tiny bit of research looking at what this property was listed for recently (it hasn’t sold), and what the surrounding similar properties are worth (~$250k).

Scott's book on estimating rehab costs, it's a must read in this area: https://store.biggerpockets.com/products/the-book-on-estimat...In addition to that, I would check out my article on due diligence.

It is not, it has limited application, and for travel expenses it does not apply at all.If you do not have a mileage log, you have to do your best good faith estimate and then pray that you're not audited.