Custom glyph name + PUA in Glyphs Mini?

How to create a symbol in PUA e.g uniE000 or uniF000, but with human readable name like search or info in Glyphs Mini ?

Not possible in Mini. One needs to stick to the convention, I am afraid, or (temporarily) abandon the PUA encoding.

I have to correct mekkablue.

It is possible. First you have to set the unicode by using a uniEXXX name. After that you are free to change the name to whatever you like.