1.9TDI losing power, hard to start, strange...

Hiyas!

Yeh, so my Octy is acting up a bit. Up til this week it was running fine, but now it seems to have developed some issues. First one is that it is often a bit hard to start. It used to just wake up when I turned the key, but now it takes time and sounds like it's coughing at first, before the idle settles, usually within a second. Then it runs normally. the other oddity is that sometimes while cruising happily along, it suddenly loses power, like there is no fuel, no response from the gas pedal. When I release the pedal and repress it, the problem goes away for a while, but every now and then it does this. Otherwise the car is running as usual. It's a PD engine, BXE. Reserved a service time next week, but have you got some ideas on what might be the problem? What I have googled up until now, are various possibilities: clogged up fuel filter (changed in december, 15tkm driven since), faulty fuel pump in the fuel tank, bad battery, cambelt timing (once last weekend made the mistake on forgetting I was on gear while stopped to let a friend out and let the clutch up -> nasty stall) and such.

So if someone has encountered the same, I'd appreciate the input!