I have found it difficult to get a smooth start from rest. At first I put it down to poor clutch control on my part, as I found I had to really put my foot down on the accelerator because I had the feeling that the car would stall if I didn't. Sometimes I don't need to do that and the car will move off smoothly - other times it stalls or is about to. I've had the car (07 reg) for just over a year now and it's just the same as it was at the beginning.
As I've been driving for about 50 years using a huge variety of cars in that time, I don't think the problem is down to me!
I have been driving for over 50 years, I experience the above, and I too have had my Jazz for over a year. I think it is down to me. The Jazz is a relatively low powered vehicle (my 1.2 litre one certainly is), it has a relatively fierce clutch (I have driven cars where you could almost slip your foot off the side of the clutch and it would still take up smoothly), and it has a notoriously fickle accelerator (you can buy an electronic circuit to smooth the accelerator operation out). As a consequence, driving, as I do, with thick soled size 10's, requires more than a bit of finesse with the throttle and clutch.
The motorcycle I learned to ride on (Honda CB100N) was exactly the same. You just had to give it enough revs to get further up the torque curve, slip the clutch, and off you went. Smoothly. I find it is exactly the same with my Jazz.
Personally I have never had any doubts about the operation of my EGR valve. The engine performs flawlessly, fuel consumption is great, no judder at any speed once clutch is fully engaged, and no warning lights or codes.
If however, you think there is an issue, then a blank can be purchased for £3.89 from eBay, two bolts and you can try it and see.
https://www.ebay.co.uk/itm/EGR-valve-blanking-plate-Honda-Accord-Prelude-Civic-Jazz-Shuttle-Petrol-engines/121234492470?_trksid=p2485497.m4902.l9144