In a debate about the Rule 5 Draft with someone about the Twins not leaving a spot open. I know that protected players has to be declared, but is it a full roster freeze? Can the Twins still remove people from the 40 man to be eligible to draft someone?

In a debate about the Rule 5 Draft with someone about the Twins not leaving a spot open. I know that protected players has to be declared, but is it a full roster freeze? Can the Twins still remove people from the 40 man to be eligible to draft someone?

Yes, they can still remove guys to draft someone.  They just can't remove any of the guys they just added.

They would have to go through waivers of they were removed anyway

Yep. most infamous example of this is David Ortiz being released just before the rule 5 and the Twins not ending up using the spot to draft anyone. 

In a debate about the Rule 5 Draft with someone about the Twins not leaving a spot open. I know that protected players has to be declared, but is it a full roster freeze? Can the Twins still remove people from the 40 man to be eligible to draft someone?

They could also remove someone by not tendering an arbitration eligible player a contract.  They would not go through waivers, rather released to free agency.  That would be another way to open up a spot on the 40-man roster.