I have been debating the issue since I read the report this morning. I have a few theories as to why the ET-Tram was there:
1) The Ipsolstai have sent one or more brothers to survey the situation to determine the truth of Bette's report (implying they heard her without acknowledging)
2) Burn, or one of his faction, put it there to aid Zachary and Enoch
3) Caleb.s, or one of his faction, put it there to further exascerbate the situation.
If Theory 1 is true, Enoch's moving it should alert the Ipsos and cause them to return quickly. They will likely order Enoch and Zachary away and make an unfavorable report about them. That will not help Bette's and Isaac's cause but should not be too harmful.
If Theory 2 is true, Enoch and Zachary are free to use it. Not only that, they would probably be considered foolish for not making use of such a valuable tool. That could count against them and also indirectly hurt Bette and Isaac.
If Theory 3 is true, Enoch has already ensured that Caleb.s has more amunition to use in his "hate the Probes" campaign. Making further use of the ET-Tram can't really make the situation appreciably worse, unless they manage to get the thing destroyed. (BTW: Do we have any idea how much punishment an ET-Tram can absorb before being damaged? Do we know if there is any weaponry aboard? Wasn't it an ET-Tram that carried the weapon that eliminated Gen?)
So here is my position:
Baring a sudden appearance of anxious Ipsolstai who want the ET-Tram returned to them, I am in favor of Enoch and Zachary using it to traverse the distance between them and the C-Lander. The scenarios I have suggested above all lean towards more good than harm resulting from using it. Bette and Isaac are in trouble because of actions they (Isaac primarily) took. Enoch and Zachary may be another irritant, but they will not be a deciding factor in all likelihood. If the ET-Tram can help them neutralize a dangerous foe quickly and prevent further aggresions then I believe they will be seen as justified in using an available tool for a mutually beneficial purpose. And, if there is a weapon onboard it could mean the difference between success and failure of their mission.
I say, let them take it and wish them victory.
Koala, Captain, Team Andrew