That's a tougher question.

I would say say that sole man time counts as total time if you are a required crewmember which includes student. That's usually how it's done in light piston planes, there's a CFI with you so you're getting dual.

If two bros want to be build twin time, the work-arounds are take turns giving each dual (questionable legality) or take turns doing safety pilot (totally legal). BTDT.


Probably. But you might encounter a logbook nazi at a regional or major airline interview, it was a thing back in the day. I'd guess today majors are more focused on your recent history. Also I have heard lately of regional new-hires getting through the interview team, getting hired, and getting through training only to have the APD decline to do the checkride because something wasn't right in the logbook. It's not something obvious like short of total time, it's going to be some technicality about some logged time not being applicable to ATP mins... while the HR lady might gloss over something like that, a APD cannot and will not let it slide if he catches it.

You pretty much need to be fully qualified to fly the airplane under the regs being used, or be a student under a qualified instructor, in order to log sole man PIC.

Also it's been recently clarified by the FAA that in order to log dual received, there must be some legit instructional purpose. That's pretty generous... all of the obvious cert & rating training BFR, IPC, landing currency, any reasonable refresher, area fam, or aircraft fam training is good. But doing the same 91 repo leg every night for a year or two and logging it as dual probably isn't going to fly. You could log it once or twice as route, area, or aircraft fam.