The "Data" path is important, because this is where output files go. The terminal path is used from the local version to run MetaTrader and MetaEditor right from fxDreema, but this can't be done from the web version. The "Data" path must be where files go, but without things like \MQL4 at the end.
The On/Off block should disable whole blocks. When a block is disabled, it doesn't run and everything connected after that block also don't run. It's like this block and the next blocks to it doesn't exist. But the block is not skipped (like there is a shortcut from it's input to it's output), if this is how you imagine things to happen.
