I'm like you in the size of model issue. 1/3rd scale is full of logistic problems due to size. I prefer 1/5 & 1/4th scale which you can get lots of detail on.
If you plan on competing to win then you are very limited in aeroplane choice. I am not interested in conforming my modeling to rules other than my own although I give full admiration to the gents that go that route.
The really good artists have documented a lot of their techniques on different forums and displayed their talents for us all to see. I really like Dietz's paintings at the Aerodrome.com, Mark Millers art at wwi-models.org, Andy Hutton articles in the old Brit sccale magazines, Donny W & other artest's at RCscalebuilder.com. Lots to learn from these gents!