Doubt on ENV variable

Question 1: If I set ENV=$HOME/myenvprofile.ksh, will my script get executed when ever I login to my with KSH. My doubt is we used to put this in .profile of our home directory. SO when ever I login will it executed?

QUestion 2: If I set ENV=`echo "hi"` or 'echo "hi" ', what would be the output. Hi will be printed or echo hi will be printed or since echo is buil in cmd of shell it wll put error on considering hi as a command. Please do help.

Thx,
Ramkrix