Hopeful looks neat but I assume you meant that the ability can be used every turn? If so, it should say "once every turn", not "once this turn".
Colosseum's "other than this" doesn't make any sense. Colosseum is a Project, so it can't be gained (buying a Project isn't considered gaining it.)
Revise is confusing. Does it mean "Gain another card, costing up to $2 more if the trashed card costs $4, otherwise costing up to $1 more?"
I think Parting is too strong for $3.
I believe the original version of Foreign Exchange said "If you have no Coffers, +3 Coffers." Did you change it on purpose? If so, the change doesn't make sense. In the original version, "If you have no Coffers" limits the power. Here, the power is unlimited, but only if you're already in a good position. But if it's the only thing in the game that gives Coffers, then it literally never does anything.