As far as diet is concerned it will almost inevitably be that advice given will vary and will not suit everyone. I was given the party line when diagnosed and started to lose weight and got my HBa1c down from double figures to below 7 very quickly. However, when weight loss stalled, even with reduced portion sizes, I decided to further reduce my intake and the only way to do that as far as I could see was to avoid avoid bread, potatoes, pasta, rice and couscous (had already totally given up on biscuits and things baked, sweets, chocolate, some fruits (grapes etc). Apart from pasta, I have some of the 'staple' carbs but very little. I don't count every day, but on Monday the only visible 'carbs' I had was from one slice of Oatmeal bread. I should add that this is not my normal days input - tonight I have fish and will have one small potato in the form of chips.
On blood sugar levels, the other half of this household has T2 diabetes and has had for about 12 years. I shudder at the HBa1c that her GP and Consultant say in her circumstances reflect good control. But, they are looking at the wider situation and, given other health issues, I can see that they are encouraging attempts to get lower levels but recognise the limitations. She was hospitalised for a few week a couple of years ago because of an unrelated illness. The hospital Consultant in tandem with the Pharmacist reviewed her diabetic medication and made major changes - mainly by removing some of the medication which they considered contradicted others. The combination of medications was, in their views 'ridiculous'. Within a very few days all was not well and the former regime determined by her diabetic Consultant was restored. Served to demonstrate to me that how treatment progresses for an individual is open to 'professional' opinion.
Nice 'guidelines', as I have said elsewhere are simply 'guidelines'. They are not prescriptive and are open to individual interpretation. Until and unless the NHS publish mandatory rules, health Professionals will interpret these guidelines as they see fit. The danger of 'rules' regarding treatment of diabetes is that medicine and treatment strategies undoubtedly evolve for any number of reasons and rules in the longer term, unless frequently reviewed and revised, would most probably end up being constraints.
On testing. I know any number of diabetics that would test until the cows come home if they were asked to do so - but I doubt that it would improve their diabetic control. When diagnosed I tested twice a day. I never did the postprandial testing many recommend, I simply recorded the twice daily readings on a spreadsheet, calculated a trend line and watched the trends move towards my personal targets. Any unexpected rise was considered. But within 6 months I was inside the upper/lower limits I set and now after 18 months my blood glucose and Hba1c is within the 4.6 - 5.5 that many think of as the 'normal' range. For a long time I have tested twice a week on random days normally before breakfast.