You have to have a user name and password to log into an Apex. If you leave it at the defaults, yes, that is dangerous. I have had my Apex and before that an ACIII, which I simply put on a different port than 80 and also change the UN and PW to something that only I know. Secure as any other site with a UN and PW.
I used to do dosing with my Apex (alk and calc from BRS), but haven't set it up yet on the new tank (it is only a month or so old). May do it, but am trying to keep the levels up currently with the type of salt I am using and small weakly water changes.