#1
Iv noticed it has 2 speaker-out sockets at the back of the amp. I was wondering if when plugged in, it acts like a head?

Thanks
#2
it could, provided you match the ohms with the amp and the cab, but why would you need to? adding a cab doesn't really have any benefits with a practice amp.
Rig Winter 2017:

Fender Jazzmaster/Yamaha SG1000
Boss TU-3, DS-2, CS-3, EHX small stone, Danelectro delay
Laney VC30-112 with G12H30 speaker, or Session Rockette 30 for smaller gigs
Elixir Nanoweb 11-49 strings, Dunlop Jazz III XL picks
Shure SM57 mic in front of the amp
#3
Yup, but don't bother buying a cab, if that's your plan.

Good as a small amp, bad for gigging.
Cam Sampbell's my hero
#4
Yea external speakers can be used along with or without the internal speaker. Just gotta match the ohms.