Making your own aircraft livery?

Taboos,disrespectful,problems,bad practice ???

You are talking about a hobby,building a model for your own pleasure.Your not entering it in a competion.So what problems would result,who would be disrespected,build it the way you want.Enjoy yourself.

Even if you post pictures here,you can head off the criticism by telling us right off that you know the markings are not right,I wanted to have some fun with it,so then what can they say that you haven't said.

Sanjaban........Remember, this hobby is about YOUR fun.  Dont worry about whatthe rivet counters say and do your thing. If it looks good to you and you enjoyed the build than mission accomplished!  

Most modelers do go for accuracy but not at the cost of it being fun.  If this hobby isnt any fun for me than i will quit it in a heart beat. Do what you love to do and if it looks good to you than go for it!

In the Golden Age of model railroading, it was considered the top of the pyramid to invent your own railroad, including logo/ logotype, color scheme, depot colors etc.

My late grandfather, who was a lifelong member of the National Model Railroad Association, was a big fan of the New York Central. But he lived in Michigan so his pike was the New Michigan Central.

Other (more) famous model railroads included the Gorre and Daphetid of John Allen. Pronounced gory and defeated...

I think it's a great idea.

I think it's a grand idea.

Oddly enough, I did a similar turn on the same aircraft -- albeit the old Monogram version -- when I took a fancy to a shield I saw on one of those bogus 'your family coat-of-arms' sites. It just looked like something that belonged on a WW1 German fighter. So with some home-printed decals and a few masked stripes I did this mad 'Blue Baron' just for fun.

Where's the harm?

if you build the model for yourself there are no restrictions on finishing and painting your model as suits you.

However,  if you are building for a competition such as IPMS there are restrictions and caveats about hypothetical markings in the standard categories.   Rather they are entered in a separate hypothetical category.