Datalayer Declaration

Hi, 

I have installed the GTM plugin however, I have 2 major issues:

1- The Pageview tag (all pages) does not fire to send the info to GA

2- The datalayer is declared after the GTM container which does not save any variables.

3- The Datalayer is declared using var datalayer however, it  should be using datalayer.push method.

How did you work around those problems?

Thank you

Sam