If you have no transponder, you _must_ call to get clearance through or in to N560, Scottish (west) look at the traffic in the E+ (and it's _not_ an airway . . . ) and either clear you through unconditionally, clear you through with a "not above FL xxx" clearance or clear you through in a height corridor i.e. cleared through between FL160 and FL140 (which is a bit tight) or make you wait for a while.
You can pretty much treat E+ as G as long as you are squawking 7000 (there are slight variations in VMC requirements in E+ from G)
Making the controllers lives easier means that most of us call even when we are squawking.
Controlled separation distances depend on what service is being provided to what traffic, sometimes Scottish maintain 3k vertical feet separation sometimes they advise on where traffic is.
I'm astounded by how helpful and proactive the controllers are considering the woeful RT by some glider pilots (I am one and I am dismal on the radio, I do have a proper license too)
We can also sneak underneath N560 in the summer, it's a bit suicidal in the winter to do that.
Main entertainment is the Logan air driver, patently born south of the wall, absolutely impeccable RT, his Tree's and Tousands are straight out of Cap 360, the joy of him being given ever more complex read backs and nailing them cheers me up no end of a cold morning . .
In short, if you want to cross N560, talk to Scottish, they'll facilitate as best as conditions allow at the time.