Renewal question

That is applicable only for holders of a Golden Visa.

The general rule is that you must not be absent from Portugal for a period exceeding 6 months continuous, or 8 months cumulative during the period of validity of the permit.

There is another more stringent requirement to consider if wishing to apply for permanent resident status after 5 years.

Posted by: @massspectrometry

Is it possible to get a visa, then an apartment, apply for the permit, and then afterwards cancel the apartment and stay elsewhere until I need to renew? And just come back and get a new apartment when it's almost 1 year so I can pass the accomodations requirements?

As x-camone has pointed out, the 14 day stay only applies to the Golden Visa program. Even then what you have suggested in the quote above would not comply with the GV conditions as the investment has to be maintained until you obtain permanent residency.
Permanent residency can be applied for after 5 years of residency, but only staying in Portugal for 14 days a year would prevent you being granted it.