if you're gonna get the ecu chipped, then i guess you may as well get a basic turbo timer. if your planning to get a power-fc, that too will remove the 180 limiter.
as for oil sender prob, i had that too.... just got an autometer electronic one.
remapping your ecu/tuning power-fc with the current setup will make a big difference (power, economy, etc).... trust me
as for alarms.... sorry cant help ya there... mine was already installed upon purchase so i had no say....