Live activity - how to see

Is there a way to monitor live activity as sensors triggers and actions are being sent? I want to see where the bottle-neck is in my system as my lights are slow to turn itself on.

No, not that I know of.
Second best solution is to add Simple Log cards everywhere in your flows.
Then you can look up what happened, and what didn’t happen, at what time a trigger was sent, if a condition was true or false, if flow cards error, at what time an action card was fired etc.
I don’t believe a flow itself can be slow. It’s mostly the wireless protocol, f.i. too many zigbee devices, or too little router devices, interference from 2.4GHz wifi or orher interference (neighbors!)
Wifi sensors are very slow by design, it takes several seconds to activate the connection after being in sleep mode (= battery saving)

There’s even a script to add logcards to a flow in one go.