Unfortunately they're geared more towards traditional agent services. 

You're confusing Traditional IRA deductibility limits with Roth IRA income limits.

My market is fairly small and I’m not a tire kicker he knows I buy and sell with him traditionally so while my commissions might not be the biggest they are steady.

It will be hard enough getting a traditional loan at your age.

This type of project here is referred to as a JADU (Junior Accessory Dwelling Unit), since it is attached to the primary residence it is classified as a JADU as opposed to a traditional ADU (Accessory Dwelling Unit). 

Having some private money at 8-12% annually that can be accessed quickly may be more advantageous than working on a deal with traditional financing with a bank/credit union when they want to due a pre-renovation valuation/appraisal and post-renovation valuation/appraisal and then go ahead and set up a draw schedule to align the funding with the project timeline and any inspections of the property... 

Which is fine.Then, when they’re on one side of a traditional sale and they want to justify either their clients offer or the list price in this small, historic part of town, they post the off market deals retroactively with the listing description as “comp only” to MLS and all the websites (Zillow, Redfin, etc).I know this because I was a buyer represented by the son on a house that eventually fell through post inspection.

I’m currently holding a traditional IRA.

Is it possible for a more traditional investor (someone not using brrr) to finance their way to 100 units?

There are many building materials that are becoming more popular as the price of traditional materials rises.