I personally feel that with anything in life, if it disrupts your peace, you have to let it go.This business is not for everyone, and only you can determine if the pros outweigh (and are worth) the cons. 

You won't be disrupting a tenant now vs. later.

The environment in San Francisco is very politicized and participating in foreclosure auctions during this period meant tuning out crowds of protesters who were attempting vainly to disrupt trust deed auctions to ‘save’ the borrowers.

Apparently, according to the owner, the tenant is a bit of a loose cannon, so my main concern is that they dont mess up the place out of some kind of spit for disrupting their living situation.

That work is extremely noisy and disruptive to the tenant's wife who works nights and sleeps during the day.

A check list for each project needed is helpful to avoid oversight and cost over runs.Might want to check how much your Property Taxes and Insurance will increase by adding another bedroom, they may be small but do add to the annual cost basis for your rental....I have a rental with a screened porch and rented it that way for 10-years, because it was occupied by the same tenant for all that time.I always wanted to enclose that porch, but - it would've cost at least $10,000 to hire it out, (with my labor included to save some costs).If I got another $100. per month rent / $1,200 per year, it would take 8.3-years to recoup my investment (break even) with zero return on investment.Your numbers will be different for a 2nd bedroom of course.Had I hired out that project while occupied, it wouldn't have been too disruptive for the tenant, but the rent would Not have gone up very much; the porch is 16 feet by 8 feet adding space to the living room.Adding a bedroom would command more rent.  

In any ongoing business a seller rarely wants a business interruption for such activities and if such needs to be done, then how those activities can be accomplished with the least disruption needs to be agreed to.

I definitely am in support of cities doing licensing and collecting taxes compared to banning, restricting, and doing everything possible to disrupt the market.

@Maureen F. we are not replacing all the dry walls, we will go over some of them with new dry walls since we don't want to disrupt the existing walls.

Add COVID concerns still running around, and you start getting into a very disruptive situation, especially when this is an investment, that should be primarily driven off your numbers.