HKG terminals are all the same IIRC. T1 is the original airport terminal while T2 is for the LCCs to use. Walk from T2 to security/immigration is longer. There is a remote LCC terminal accessed from the main one so your gates might both end being up far apart.

If your friend can do web or phone check in, he/she should be o.k. If not, go with them to check in.

I just saw a note on a recently-issued Malindo ticket that if you buy a ticket for someone else, that someone else should be provided with a photocopy of your ID and front of the CC. Saw no such thing on my two current D7 tickets.