I am by no means an expert and my very first salt tank was a nano .
With that said there is no reason you can not start off on a nano . Most of it is trial and error , and learning from the failures and experinces of others ....I have had many failures in the nanos , things that I just did not understand would it have been diffrent with a larger reef perhaps , or perhaps not , we will never know ... Sometimes I find myself still pushing the envelope and failing but to never fail is to never learn , this is how we have come so far , people push the envelope every day and in every way with nanos ... Would I do an anenome in a nano I have but they quickly out grew my tanks so now I would not ... Would I try sps sure if I had the lighting for it I perhaps would but I also dont have the base knowledge other than they are more difficult than softies,zoas , and lps ,They also require diffrent specs such as possibly dosing diffrent trace elements that would be used quicker in a nano so I would not be able to try them with out further research for me to be more comfortable ... Even with MH you can keep the softies as listed above pph but you would need to light acclimate them. With the 80watt light those and most lps should do just fine in a nano ...with out the high price of a fixture and what you may need to run it
You have to just jump right in to learn , sometimes joining sites with just a nano base population that can help you understand the smaller reef...Just because they are smaller you need to watch more closely your perematers and must stay atop of your top offs and your weekly water changes ...just to help export the DOC that will build up . In talking with those that have a larger tank vs a nano here is the diffrences I find :
Nano---
Less intense lighting needed
skimmer not needed if water changes are done and bioload kept minimal (Fish, feeding wise)
Easier to move in future moves
quicker to stock to capasity (only a few frags wil fill most nanos up LOL )
Larger-----
require more intense lighting ,
require skimmer but will still need a weekly /monthly change of water
more upfront costs such as lr and corals if wanted ...
I guess what I am saying is each has their own "special" requirements and has thier own set of problems that can present but there is no reason that by going sloooowly with a nano that it cant be your first salt tank