I vote for robbing the trader, because of the following:
The only magical artefacts we have are teletalk wands, Tubikh Rrahim staves and the Wand of Heroism. Either we don't want to sell them, or they are worthless to him. Every other spell we have is just that, a spell, not an artefact.
Arstotzka has their Wand of Fireballs, which is is probably obsolete for them by now, they have their amulets of magic detection, they have crystal weapons. All of these things they could easily sell to the trader.
Thus, we stop trying to sell him crap and just rob him of his wealth and the artefacts he bought from the Arstotzkans. We can then throw expense credits at everything and reverse engineer their artefacts for our own ends.
Voting Against the order to Deploy Ballistae on the boats only: [5] Happerry, ATHATH, Mardent23, Sosoku234, Devastator
Voting For the order to deploy Ballistae on ships only: [2] Kashyyk, NUKE9.13
Giving the Trader the Wand of Gust of Wind [7]: ATHATH, Mardent23, Sosoku234, S34N1C, Taricus, Happerry, Devastator, NUKE9.13
Giving the trader Storm Strike [4]: S34N1C, Taricus, Devastator, Happerry
NOT Giving the Trader Storm Strike [1]: ATHATH
Giving the Trader Teletalk Wands [1+1]: Happerry
Provided it gets us both expense credits [1]: NUKE9.13
Don't sell anything to the Trader [1]: Detoxicated
Robbing the trader [1]: Kashyyk
NOT Killing the Trader [4]: ATHATH, Mardent23, Taricus, Happerry
NOT Telling the Trader About the Existence of Arstotska [2]: ATHATH, S34N1C He already knows.
Also,
evicted: if we limit ballista to naval use only, will that increase the number of ballista the navy can use, or will we just be hampering ourselves for no reason?