Pirates and Privateers and Mercs

1) Merc shipping on military duties

Mercs willing to accept "hot" assignments would
 want assurances of fleet-sponsored repairs
and high premiums on the operation. Use of mercs for these roles, while not
unheard of, would be rare. The main use of mercs would be to free up national
fleet elements from mundane tasks which mercs would do without asking for the
kitchen sink. Recce, intel
gathering, shipping security, system patrol -
mercs could do these things.

2) Privateers and Pirates

Privateers would require a Letter of Marque and are (IIRC) operating as an
extension of the government that hired them. Ergo slaughtering crews etc. is
probably out. They neither want nor need to do this, unlike pirates. In fact,
they'd be anxious to prove to a civilian captain that they are in fact
Privateers, and when the battle is joined, they would (I think) fly the
appropriate flag (or maintain the appropriate electronic signature?).

The trick, of course, would be knowing if it is a pirate (who'll probably kill
everyone to eliminate witnesses) or a privateer (who probably won't). I assume
national gov'ts would pursue pirates who masqueraded as privateers quite
intensely. This is of course a good way to besmirch an enemy power (disguise
yourself as one of their privateers, then act in a vile evil manner).

As for ships captains not being anxious to surrender.... I'm in a thrust 2
merchantman with maybe one or two beam 1s. My escorts are
either non-existent or dead. I'm facing a thrust
4-8 raider with some B-2s, needle beams, and
perhaps a squadron of fighters... my options are surrender, try to run and be
crippled, or if my luck is bad try to run and die. Hmmm.... which do I take?

Raiders would need less firepower and more speed to run away from (or catch up
to) merchies and their escorts. They'd want mass advantage.

As for escorting ships: You can't compare exactly to today's world. Think more
of the 1800s or earlier. Today, the world is a "small" area (like a big bay).
Fleets from main powers can cover or surveil most of it. Not so in space. The
gulf is too vast, the tech not there. Humanity is far more far flung.

Yes, you _can_ send a warship anywhere a
merchie can go. But you might not. You've got a limit of warship numbers.
Sure, 1 in 10 convoys is escorted (probably the really important ones). But 9
in 10 are not. If I double my escort commitment, I double my odds of messing
up pirates and privateers. But
I rob somewhere else - system defense? main
force? If I start building a pile of escorts to defend shipping, then I eat up
yard capacity and money. Paying for privateers is a great
investment - a small number can cause (in weak
defense situations) a disproportionate loss of shipping tonage, or (in strong
defence) can draw off a whole pile of enemy fleet elements out of proportion
to their number (defending like this is waaay more expensive than attacking)
and it might choke off the flow of goods, which further hurts my enemies.

It's a case of balance. If you have enough money to do everything, sure you
escort every convoy. If you don't, you escort some randomly, some important
ones intentionally, and you evolve convoy doctrine so the merchies can do
their best to survive (and probably arm some of them slightly). Oh, and you
probably do have to build a few more escorts, balanced by your other budget
issues, or rob them from some other militarily useful place. The extent to
which you do this determines the extent to which privateers are effective and
how much it costs you. And no one said privateering was entirely safe. It is
safer in the early stages of any conflict....;)

Tomb.