Task force question
 

Is it normal for all the task forces that I have intercepted to be a old liner and a new liner? I don't see any with any other warships other than the escorting cans.

Sounds like you're running into invasion forces. You're probably in the early war.

I can attest to the fact that you'll find many types of task forces as time goes by.

If you start a career in 1941 out of Manila, just hang around the NW coast of the Island on your first patrol, and you'll almost surely run into a nice big task force - BB's, CA's, the works :D

1942 is also a busy year for the IJN's carriers and major combatants, down around Borneo and Celebes, Java.

Is it normal to run into unescorted invasion forces too?

Unescorted convoys of all types is not unusual. This is also consistant with history.
-Pv-

In the game, ANY group which is lead by a warship shows up as a "task force."

So a troop transport, just running troops might be a TF if the lead ship is set to be one of the escorting DDs instead of the liner.