To be honest, I like the idea of having rank in the names. Several times I have been involved in large tangled battles where it has been unclear what the chain of command is.
So, there are two problems:
1) People with long names. Well, this is a problem that will go away, once a system is implemented, new recruits will be aware of the restriction to name length. Those of us who need to change now are few.
2) Clarity. Long strings of chars can look messy and confusing. There is a really simple solution to making the ranks obvious and short :- numbers. We have 8 ranks, so what I would suggest would be:
A leading char, say '~' and then a single number to indicate rank.
Keep the number 0 for when the Queen, or a vessel containing her representative, or Ambassador etc. is in the field.
Thus, when in space, you will be subordinate to those people with the lower number - easy!
The privateers could also be marked the same way to show who is in charge.
Capital ships could also use the same system
~1 Flagship Battleship
~2 Destroyer
etc.
This is somewhat similar to the 'type' system actually used by the Royal Navy
(Sorry if I got the rank orders wrong, but you get the idea)
Hope this helps, chaps. I am not worried by having to shorten my name for the cause!