How to connect bathroom fan and make it smart - electrical plan and automations

Currently puzzling over the following, please bear with me.

I’ve bought a bathroom fan which itself has no functions other than turn on/off in 2 different power levels (MAICO ECA 100 ipro), since I wanted to do the whole smart turning on based on humidity etc. via automations and HA.

I have a double switch for the bathroom, put not one that closes/opens contacts but a pulse switch (essentially it constanctly has electricity and just sends an impulse when pressed, the smart relay is then what sends on/off signals to the lamps behind it). That switch is also connected to a smart Fibaro double switch relay. Here’s the wiring diagram of it:

The idea is: Q2 is used to solely switch on/off the bathroom lights, Q1 will be used to switch/on the bathroom vent.

From this switch+relay arrangement, I’ve got a 5-wire cable going to the bathroom vent. On the vent itself, there’s this wiring diagram:
and the wiring diagrams from the manufacturer for different arrangements:

Here’s what I’m trying to figure out in my head: if all I want to do is just turn it on/off with the switch, it’s easy. Connect Neutral to N, and Q1 from the switch toeither 2 or 1 on the vent (depending which power level I want), done. However, some questions:

  • What does this dotted line from N through the lamp to 2 on the vent mean? If my lamp has is not connected to the vent (as it has its own button Q2 for switching), can I ignore this or what does it mean?
  • If I want to be able to execute the following use cases, is it possible/how would I need to wire it/what automations to set up in HA?
  1. Automatic turn on/turn off based on humidity (humidit would need to be provided to HA via a separate sensor)
  2. Let user decide to either a)immidiately switch vent off, b)have it run for 5 minutes and then switch itself off or c)have it run for 15 minutes and then switch itself off

For both use cases, it would need to be able to receive constant electricity right? 2) sounds like it could be handled by single/double/tripple button press, Fibaro switch relay is capable to recognize those differences and do different things based on them. For 2a) it’s probably just the usual on/off function of switch, for 2b) and 2c) it’s maybe 2 different automations saying turn on switch.bathroom_q2, wait for X minutes, turn off switch.bathroom_q2 and then let the fibaro relay activate either automation based on double/tripple press? Am I thinking about it correctly?