What sorts of challenges would fit for a noble or very wealthy character? Obviously we have a background of fiction to draw ideas from but few Traveller games seem to deal with the idea.
From a gaming point of view they both have the same problems - the player could buy their way out of trouble ("Ancient ruins? I'll hire a merc company and the world’s greatest professor for the expedition"). Stopping this by upping the threats rapidly becomes silly or a Monty Haul scenario. So you have to clip their wings by spinning scenarios which require brains over brawl.
To separate the two types (noble or rich) is to define their job. The primary difference between the two is one has 'sanctioned' power the other has 'buying' power.
Starting with the nobles (sanctioned power), what do they do to earn that power? Obviously they have to do something for the Imperium and you use that as the basis. A PC wouldn't be happy stuck at the usual noble desk job so select something that requires a hands on approach.
Eg. The Noble is a 'circuit judge' for the MoJ. They have to trudge along a string of backwater frontier worlds dispensing Imperial justice when required, with occasional diversions for 'emergency sessions'. It may sound boring so you spice it up with the 'spaghetti western' feel. Assassins, special investigators, corrupt officials, wrongful arrests, murders, etc. Things which require the deft use of iron and velvet hands to solve.
And your patron Noble will be upset if you get to many cases wrong...
Rich can be further broken down into 'independent' and 'dependant'.
A Vice president may be rich but is dependent on his employment. However this may slip into the 'lose your money' or 'rich problem solver' tropes so you change it slightly.
Eg: The person is rich and powerful because they are member of the local equivalent of the Illuminati. The Grand Master (or whatever) sends them out to solve problems and they have a nice slush fund assigned to fix the problem. Think Deus Ex types - each trying to manipulate the outcome on a planetary scale to suit themselves while countering the opponents. Running and Gunning is _not_ what you do for secrecy. "These people, they're like ghosts. Always in the shadows, hiding behind lies and proxy soldiers...".
Independently Rich is the tricky one. The PC has cash with no obligations to tie them with. A way is to ask how they made their money and how do they maintain it. You could have them running a small mercantile company, but this can fall into the 'lose your money' or 'Merchants and Markets' scenario.
Eg: The PC is an information broker (Like the Shadow Broker from Mass Effect)
. They bounce around worlds collecting juicy information and selling it to those who pay. They use minions to collect the actual data but they have to collect it themselves and keep on the move to prevent getting tracked. Sure you could use an Xboat but the info could be months out of date as opposed to weeks. And of course maybe they have a FTL comms artefact to give them their 'uncanny' ability to know what is happening, something that every power in the region would want for themselves.
On Edit: Forgot to mention. Another big factor is what the players want. Sure you may like 'Spies and Conspiracies' but the players may want to play 'Bombs and Blasters'. But that is for the specific GM to work out as they know (or should know) their players tastes.
