TickTime should be 100ms by default (BarPeriod = 1), can it be set to 0 or 1?

Yes, 1.78.5 can read the bid-ask spread from .t1 with marketVal(), great!

Is it possible to observe and trade more than one asset at 2 Brokers with one script (renaming variables SpreadA/B, CommissionA/B, Difference and Threshold to asset-individual ones and list the further asset(s) in the run function) or are there limitations e.g. in the tick function or is it recommended to use seperate scripts?