login on two computers & yosemite compatibility

[avery.ng]

hi, can i check that, from what i just checked,

a purchased creative cloud plan can be used on two different computers at the same time

does it mean both computers also have to login to the same adobe account in order to use it?

or it could like microsoft 365, send an invitation to anther person who shares the plan together?

because another person might have his own adobe account already and tie with behance

i checked that currently the yosemite beta is somehow compatible with the current CC versions except the java version?

may i know in fact which one should i download?

thanks