Between the two of us, who's claim should I submit dependent's expenses, medical, and charitable donations to make the most in refunds? My husband makes more income.

Generally, you should group all charitable donations and submit on one return, as this maximizes the amount in excess of $200 that attracts the much higher credit rate.

Generally you should also group all medical expenses for you, your spouse and dependants and file under the person with lower Net Income, in order to have only a single 3% deductible instead of two. Also the deductible amount may be lower.

These recommendations aren't always applicable, for instance when the lower income partner has insufficient tax payable to use either of both of the above credits.

Another case would be when both partners have high Net Income, enough to invoke the maximum Medical deductible of around $2200. In that case it woulldnt matter who claimed Medical, although it should be the same person.

For charitable donations, if one person has Net Income in the highest Federal bracket (33%) then the donation should go on that person, as that rate is credited federally.

Subject to the above, it doesn't matter who takes Disability, as it is just a standard non-deductible credit.