This is not Real Estate exclusive either.

(more philosophical questions than anything)-Does the 121 exclusion still apply if I rent it now and sell it a year or two from now?

This has no effect however on any eventual capital gain calculations.If you’re talking about Selling, you have 3 years from the time to turn it into a rental to sell it and still qualify for the 121 exclusion. 

Good news is that the numbers work on a relaitivley wide range, all the way up to the more exclusive North Shore communities.House hacking is the single best way to get started, hands down.

Do you qualify for any exclusions to stop the reassessment?

All of the big and small operators are using them exclusively because they are not only a one-stop resource for everything you need but because they track it all for you and allow you to know at a glance how much you've spent on each house in parts.

I'm fairly certain this owner would not be reachable and next step of action would be to post notice in local newspaper.2) I see some liens with one 2018 tax lien listed but the owner hasn't paid 2019 / 2020 taxes but there are no liens created for 2019 / 2020. 

I'm most looking at EFU (exclusive farm use) and WR (woodland resource) properties which seem to allow it, but have strict rules regarding dwellings per acreage, where you put it, and usage etc...

They also specifically mention covering R22 in older systems, which is awesome - that's another hidden exclusion by other companies.

@Vik C.Its a co-op with likely maintenance and an additional fee to rent it out.This will likely not make a good investment.You are likely also eligible for the 121 exclusion if you live and owned the house for 2 out of the last 5 years.