I agree that acting on your own initiative and being proactive are key requirements in more senior staff.
But your dh sounds an arrogant twat who didn't express this well! Nobody never makes mistakes! We all do we're bloody human!
Jobs where I've been there long enough for promotion aspects (ex was military as was dad so I've moved around a lot due to them) I also went to the "boss" with ideas for improvements.
This has been from minor suggestions like to stock more vegetarian items in a small supermarket as there were very little and we the shop floor staff were frequently being asked for certain products which we didn't stock. As I'm veggie myself manager initially thought it was a personal thing so with his permission me and the other shop floor staff kept a simple record in notepads of how often we were asked for certain of these products over a month and present that to him and he was surprised to learn how often it happened, he got the stock in one month on a sort of trial basis and we sold out in a week! He then agreed to stock more and it was very successful not only in terms of selling these particular products but in attracting higher footfall/custom generally.
To overhauling a database used by the entire uk military that was a pain in the backside to use as it was! I suggested it, IT dept was brought in for that side but I was able to communicate to them what the issues were that users were having plus there were a number of glitches that they were unaware of but were simple to fix. Result the database was much easier to use and this reduced pressure on another linked dept who were only really supposed to deal with certain aspects of the info mainly emergency based where previously they were dealing with a lot of frustrated and confused day to day users of it.
I have to say I think you need to really work on your confidence and assertiveness too (possibly your husbands fault!)
Look into taking an assertiveness class - maybe you could even suggest your employers run a workshop for all staff on this? If they deal with clients/customers these are fantastic for teaching how to deal with complaints etc
A manager should be able to confidently discuss pretty much anything with colleagues and certainly subordinates.
If you aren't confident/comfortable discussing improvements to a database how would you cope holding interviews and hiring people or even harder handling disciplinary action or firing someone? Cos let me tell you that stuff is tough!
Consider do you really want a promotion or is it just more pay/you think you're supposed to?