Hi cafeiguana and welcome.
The Cafe Ristretto paired with the Breville burr grinder is a fairly low entry point.
I would hazard a guess that your fondness for espresso will press you to a better combination when funds allow.
For the moment though, its all about the taste, and if you are happy, then keep on trucking!
The quickest and usually most noticeable way to jump in quality is with a good grinder.
Sadly, the Breville isnt really in that class. You need to look at something like an Iberital Challenge, Sunbeam E0480 or E0450 or similar. Have a read of the grinders section to get an idea.
The pressurised question comes up quite a bit.
Have a read of replies 3 and 4 from this post
And keep asking questions. Were here to help you with this obsession!