It sounds like your questions were already answered.
I only disassemble mine after about 5 or 6 painting sessions or more.
I spray thinner through it, backflush it with thinner, spray some more through it and then clean the color cup or jar, etc.
I don't remove the needle every time but you can if you want.
Just remember to be careful with it as everytime you disassemble it you have the potential of damaging something if you are not careful.
I also recommend you get some Badger Needle Juice or Medea Super Lube for the needle and trigger. You can also use glycerine from the drugstore if you can't find the lube.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon