ah, the trade again.
You want to get farming bots into the game? Cause that is how you get them:)
that sounds a bit premature, like trying to avoid a risk others faced without trying to learn from it. if you would have problems with bot farmers, it would be actually a good sign for the game’s popularity.
also, you do not have to introduce GS into a trading system, or you can offer simply anything that is on trade as copy for GS to do it the business way, or do 1GS trade fee as the “neutral middleman” solution, etc.
it’s okay not to go trade, as there are more things to care about than bot farmers, like inflation, scaming, etc.
I rather want to put the spotlight back on the issue, that trade will always come up, because parts of the game design are inspired by games which actually were built for trade.
the drop rates in open space as non-personal drop are an example. the non-availability of items in rewards for a gamemode, where it is actually used, is a further example (monos, neods), which again usually is done with rare drops in games where trade is a thing (wow, diablo, etc.), where different “raids” and “bosses” drop items and the system ensures, not everything is usable by the current player, and adds a bit of random loot specificly for the player. this ensures that the “optional” trade becomes a social feature (opposed to games, like elite where trade is done only with “trade items” becoming a game mode)
these things might seem “random” but they were very carefully designed game design decisions. having useless loot in the random tree usually has a good reason.
i do not see these reasons in the looting system in SC.
the reasons are mostly always historic and chaotic. like the exchange, which offers credits for GS in a value rate, that makes it quite a bad deal. but it wasnt always a bad deal.
Funny, usually f2p games have this feature, and its always a bad deal, so nobody usually notices. I bet it was introduced to be actually a good deal back then, because it was quite a nice amount in the old system and its rather spendy economy, which was also a lot less credit friendly, even if it is still hard, but atm. its a way more fair income system there. So maybe, it was even added in the thought “no our game will do it fair!” and now, historically, it became the same feature like in every other game, where you usually would never spend money on the standard credits. Which circles back to the avoiding problems part. You can’t grow by avoiding problems. You basicly invite them in the back door.
@OP
you will notice, that if you use premium, your credit income will skyrocket. while the amounts offered in the store are really easy to farm nowadays, without premium, you will usually still by playing the game non stop successfully, stay at a certain credit level - whatever you currently have if a couple thousands or a couple hundred millions. for that (being without license), the deal still kinda makes sense, especially if you try to unlock the ships faster, or need them fast, to buy something half price. but you are right, most of the time, you could spend your GS better on other things. like paint, as the credit influx becomes kind of manageable once you finished unlocking and buying. 
and its certainly not a deal representing the value of credits.
