Please insert code as code. It will possibly not be readable otherwise.
You may edit your question with this regard to get it clear.
A cell containing a formula cannot be blank by definition. Next to blank should be the empty string (0 characters) and this should serve the purposes in most cases.
The alternative part of your first if (nested first level) seems to be IF(E12<e11,$e$3,$e$2,if(e12=0,""))
. (Why lower casel letters in references?) The IfYesPart is $E$3, the OtherwisePart is $E$2 and the following ,if(e12=0,"")
is a (faulty) fourth parameter the IF() function cannot accept.