Hi judojamesg
24 years into this career already so I think I can answer some of your questions. But be aware that I am probably a cynic.
How do you pilots cope with family life? : Depends, long haul / short haul, roster pattern, but the biggest influence: your partner
Are you away all of the time?: No just most of it (my personal present experience
Does the time away get less with higher seniority levels?:
Absolutely not, probably worse. Longer trips, training work (for those involved with that). Those with reasonable bidding system might though work out better patterns.
Seems to me we are working more and more, days off are bare minimum (and then the inevitable phone calls from Crewing; can you please...)
Somebody else have this feeling?