I was wondering if there is a way to make my delegated harvesting node more secure by adding multisignatures to it. Is this possible and if so will it effect my harvesting?
you dont need to make it more secure. xem are never sent to your delegated account. so there is no need to make it multisig. its perfectly safe already. thats assuming you havnt put the private key of your xem holding account on the node - which would be a really bad idea.
Speaking of delegated harvesting and multisignatures what will happen if
a normal account which has an activated delegated harvesting is converted
to a multisignature account?
Will the delegated harvesting work without any changes after the main account is converted to a
multisignature account or the deactivation of the delegated harvesting is required
before the account conversion and then a new delegated harvesting activation is required after the account has been converted?!
I believe an account can be turned into multisig and preserve its vested balance and harvesting status without a problem.
I believe you should, however, activate the account for harvesting (regardless of your vested balance) before turning it into a multisig account, otherwise signing the harvest activation transaction can be troublesome.
No need to have all your balance vested again.