I have just purchased a three pack Deco BE65 to improve the poor EE WiFi around my house. I get 900mbps to the router, but using the EE boosters I'm lucky to get 150mbps less than 10 meters away and we are in a new build house so it's not got thick walls. 
 

I set up the BE65 today but it wouldn't allow me to connect directly to the EE wall modem as the light on the main deco just kept going red, so I ended up connecting through the EE router after switching off WiFi on the EE router and I'm now getting 800mbps through the Deco's where I was previously getting the poor speeds, which is brilliant. 
 

My questions are -

1/ Am I unable to use one of the BE65's as my main router whilst I have an active digital phone package with EE, even though I don't use it? I've read that might be the issue? 

2/ When im setting up the BE65, do I need to specifically select PPPoE and put in a username and password, and if so where do I get that as EE said I don't need one? 

Sorry if these are basic questions but the instructions aren't the best and I want to do away with my EE router and use the main Deco along with the 2 other units as my network. 
 

Thanks & I hope that makes sense.