IR(r) / IMC rating? 15 hours is doable. But then the aircraft I have isn't fitted with an ADF so that means I'm doing it without all the NDB stuff (which is fine).
The 15 hours of IR(r) or IMC rating instruction can go towards the CBM IR (and potentially more if your IMC instructor has a full IRI rating). Therefore there is every reason (in the UK) to do that rather than the EIR as a stepping stone to a full IR.
The issue with the EIR is that you can't do approaches with it - you need to essentially make sure both departure and destination are CAVOK before you leave. What if you've a problem or a diversion mid-route? You need a way to traverse into VFR for your take off / arrival. Does it not make a lot more sense to be able to follow the standard approaches instead? Makes ATC's job much easier!
If you are in the UK - a sensible route is IR(r) + experience -> CBM IR.
About education during a PPL? Training to deal with inadvertent IMC is required now. You are only tested on doing a safe 180 out of cloud, but the EASA mandated syllabus includes climbing / descending and turns under the hood. I understand this is one of the bits missing from some of the lesser qualifications (LAPL / NPPL).
Oh - and the IR(r) can be added to an EASA licence for at least the next 5 years (the deadline mentioned has been removed) and once you have it - they can't take if off you.