Best of all, seal that cement board with RedGard before tiling.

Leave 3/16” for imperfections and buy matching grout/ caulk that doesn’t require annual sealing.

@Antonio DeFlorioI've also seen:Buyer to pay for survey and provide a sealed copy to seller.Buyer agrees that their attorney has reviewed the contract and accepts all terms.All contingencies waived.Should seller decide to appeal previous year's property taxes, buyer is to pay their pro-rata share of the legal expenses to do so.Like you said - buyer pays all closing costsAnd all of these things are always buried in the middle of 16 pages.

The house was beach pink with doors falling off, crap all in the yard, smelled like a cigarette, moldy carpet glued to the sidewalk outside, etc... after we finished making it beautiful and white, pulling carpet and sealing sidewalk with a nice color, landscaping, etc, a lady teacher yelled "thank you, that really transforms the look around here, we appreciate all your work".That was cool.

Replacing tenants would cost more than sealing the basement for a little rain water or snow melting in my opinion.

Just paintin' er white.My vote is repaint it.Coming from the staining/sealing world, stripping it will not get it all and be a terrible mess and cost a fortune.

Seal the gaps. 

The tub has a swing door that allows you to walk in and seals when using the tub feature.

You could provide both with the addition, then seal off the interior connection and only use the additional entry when converted.

If mice become an issue (so far only in one house) we will set traps and seal possible openings.I once had a tenant who moved from New Jersey who, I learned (AFTER the lease signing of course) had very bad OCD and was terrified to the grasshoppers outside.