That's a great decision, but now you have to bother about understanding how the Google Tag Manager pixel management system works....It can really be a hassle.
Let me save you all the trouble of learning & managing GTM because I've already done that for the past 5 years as the Tracking manager of two international companies with high demands for pixels management.
I can easily create the basic setup within a WordPress website with GTM with nothing in it, or create a more advanced version of the setup that is Analytics ready or create a setup that will jump start your website for advertising in Google AdWords.
So don't waste your time, just contact me & let me set it up for you.
It shouldn't, since Google has invested tremendous efforts in order to make GTM as suitable to any kind of website in the world.
Yes. You have a google account the minute you open a GMail account or use Google Maps or any other Google product.
You will have all of your external products' pixels installed and managed in one place. This way the speed of you website pages should improve & problems with pixels can be treated faster.