This appears from the front view photo at least be a very mild case of symmastia (2 breasts meeting in the midline)
Agree with the other surgeons comments here. Unfortunately there is not a non-sx treatment that will help this. Options include a) trying to suture the affected skin back down to the chest wall b) changing augmentation to a sub-muscular implant placement with a modestly smaller implant (more likely to work).
IMO get a second opinion.
Breast asymmetry can have multiple components including differences in volume, breast footprint, ptosis (droopiness), nipple position and more rarely significant skeletal (chest wall) asymmetry. It can being frank, be a very challenging problem in some cases.
But here goes. From your photos the obvious asymmetries that I see are in breast volume(projection) and nipple position, although as other authors have noted there could also be chest wall asymmetry present too. The first two issues are readily improved upon, the third if present can be harder to correct.
Without a in-person assessment it can be hard to accurately determine the relative importance of these factors and come up with a plan to improve things for you. Hence the reason for the disparate views of my fellow surgeons. Get a second or even a third opinion before undertaking any further Sx.
Yes, all of your stated goals are attainable with an augmentation + lift.
A lift alone will not giving you any lasting upper breast fullness, nor increase the size as you desire, even if it is a modest increase.
The short answer to your question is maybe. You look to me to be a 'borderline' candidate for aug versus aug/lift. The 10 cm measurement is a guide only and is not a hard and fast rule as far as i am concerned.
Judging from your pictures I have had similar patients some of whom have opted for implants only and some of whom have opted for a lift plus implants.
The answer is tailored to the individual patient/circumstances. Some patients are very averse to having additional scars on their breast and some patients are very particular about the shape they are trying to achieve (thus requiring a lift as well)
In this setting I find 3D simulations such as Vectra very helpful as they can give simulate the results of both approaches. Interestingly, I have been frequently incorrect in my assumptions about which patients opt for augmentation versus aug/lift based upon their initial requests.
My advice would be to seek out a provider who can perform such simulations and confirm what it is you prefer/dislike before proceeding