i dont know is this a good idea,but i think we should try it.
1.Make TC and ST can use together, like a item is 5k TC ,2 ST,after add this,you can just pay 2500 TC and 1 ST to buy this item.
2.If NO.1 is not very convenient,toribash can make a exchange,to change TC to ST or change ST to TC.
3.Add one "transfer ST" buttom,same as "transfer TC",just change the TC to ST.

These are my ideas,all my hope is toribash to be more convenient.