Hi Carrie - I think you mean estradiol (oestradiol). yes that is quite a high level but not exceptionally so, and yes if the blood is taken from the same arm to which the gel is applied this can skew results as far as I understand - and also probably depends when the blood was taken in relation to where you apply the gel?
You don't need utrogestan if you have the Mirena coil and it is still in date (officially 4 years for HRT but can be effective for 5 years I think). Excessive progesterone can sometimes increase hot flushes in women - some women on cyclical HRT actually increase their oestrogen whwn on the prog part of the cycle because of this.
Weight gain can have a variety of causes.
I would stop the utrogestan, see how you feel after a couple of weeks and if still experiences flushes and sweats then try and increase the gel dose as you auggested, and see how you get on.
Hurdity x