We remodeled 2 of the units and have done a substantial amount of work around the property, and we have roughly $270,000 in equity. 

Spend more time then anyone else doing all substantial services.

The manager can and has unilaterally amended the OA, and it seems simple enough to add a sentence that says ownership will be determined by contributed capital, which is consistent with the substantial economic effect [and whatever language is required] of the partnership. 

The lot is steep and we had an architectural engineer outline how the cost to remove boulders and build up high (where there would be a better view) would be quite substantial but building lower by the road was more feasible.

What are you seeing to substantiate this?

Condo fees are substantial and are usually 1-3% asset value which hugely hurts your money picture. 

Sb1482 explicitly states you cannot substantially change lease terms.

I am fortunate enough to have access to the VA loan and have a bit of reserves saved up for anything cosmetic needed or wanted before moving in and renting out any of the units but not enough for a substantial rehab.

At that time, my net worth was pretty low, and as an engineer my income wasn't substantial either so did not make more than 200k/year.

Actually people who do don't invest there, they park their (substantial amount of) money.