Fluval flex 15 nano reef

[Konst]

Hi guys! 
I’m new to nano reefs and after a long time of research and investing I’m almost ready to start my nano. So far I have the following, 

Tank (Fluval flex 15)

Ro/di 

Return pump (Sycce Syncra Silent 0.5)

wavemaker x1 (jebao sine wavemaker slw-10)

lights (Fluval marine 3.0 Bluetooth mounted with silicon on the original cover*)

heater (dennerle nano heater compact 100w) 

ATO (autoaqua smart ato duo) 

substrate (carribsea fiji pink) 

skimmer (Fluval sea ps2 mini skimmer)

salt (Red Sea coral pro salt) 

water parameter testers for the cycle 

7kg marcorocks (base shelf and plain) 

dr. Tim’s ammonia 

(I also plan to replace the stock return nozzle with random flow generator nozzles)  

the only modification besides the lights on the stock lid I have done is some tweaks in the filtration (plug in the bottom intake and I have swapped the stock filter with the intank second chamber media basket) 

I have some questions regarding the cycle. Can I do it with just relying on the dormant bacteria inside the Fiji pink sand and seeding them with dr tims ammonia or I have to buy bottled bacteria(keep in mind I don’t mind waiting extra time for the cycle)also what kind of media am I supposed in filtration during the cycle and what kind of media am I supposed to use during the ugly phase? Also I have a question about stocking besides the CuC is it plausible to have 2 clownfish and a watchman goby? Or 3 fish are going to be overkill in such small tank? And I have a a question about the filtration, water from chamber 1 goes through the media basket in chamber 2 then it is forced down from chamber 2 to a smaller chamber then it goes to chamber 3 which is the return pump and back to the display. Should I block the intakes from bottom to top exposing some on the top side so the water is in fact forced from top to bottom in chamber 2 and not from the sides as it is originally? 
 

Any advice is much appreciated! 
Thank you! 
 

*I need the lid because my cat hates every living being including fish!