It might cause me financial harm as I have to sell more stocks and might pay short term capital gains vs long term capital gains.

Probably that may be causing confusion.

You are allowed to charge for ALL damages beyond ordinary wear-and-tear.

And that something caused your intent to change. 

It could be that you just need to sell this property as it is not actually an investment, but something that is causing you to lose money by not obtaining occupancy, and certainly not getting any type of appreciation, equity, or ROI.

Unless the medical condition meets the state criteria for early termination and that the medical notice does not appear to suggest that, you cannot terminate the lease outright/immediately but that you will begin to market the property for rental and upon securing an acceptable tenant, the lease can be terminated pending a satisfactory property walkthrough indicating no damages. 

. ****, I do that in the REI aspect but that's just cause it's a growing % of the portfolio.

I understand this is not a requirement, but I have never received a damaged unit from an inherited tenant or any legal issues.

However, I'm unsure about the costs of maintaining the SL in Spain, especially cause I read in some forums that these costs can be pricey..Do you have any views on the above based on your experience?

What problems with the other tenants (who they likely know well) could they cause?