Sounds like OP is on the right track. Here is what works for us: We each have our own Amazon credit cards for personal purchases, since we both buy a lot of stuff on Amazon. The Prime fee is paid from household expenses.
I use Accountedge software, both for business and personal bookkeeping. I'm not sure how Quicken works, but in Accountedge I just allocate/budget $200 per month for each Fun Fund, which rises to $500 for the month that is your birthday, as well as for December to cover gifts.(Accountedge allows for different amounts each month.)
As the months roll by, the budget builds up. When someone buys something (check or credit card) that is personal, it logged to the "Fun Fund" expense, just like Groceries or Auto etc. At the end of the year, if the Fun Fund is underbudget, we roll over the balance to the next year by adding it to the January budget. If over budget, then January starts off negative.
So if I ran the budget from Jan - May (5 months), the budget would be $1000 each ($200 x 5). The program will say:
Fun Fund A - Actual $900 - Budgeted $1000 = -$100
Fun Fund B - Actual $1200 - Budgeted $1000 = +$200
We really don't pay too much attention to it, and somehow it never gets too out of whack. My DH tends to buy more clothes and shoes than I do, so he's usually over spending, but I just tell him that and he stops for a month to catch up. I might find that I'm way underbudget and will buy a nice piece of art, or something special.
In 23 years, this system has worked really well. $200 isn't much if you need to buy tech stuff though. If we want to buy something like a $3K camera, iPhone, iPad, etc., I purchase it from the business account, we make sure to use it in our work and then write it off. Anything we buy for the business is 43% - 47% discounted, due to self-employment, Federal and State taxes. Sometimes a big purchase at the end of the year will drop us from 28% to 25% tax bracket, or keep us inside the Roth limits, so I run those numbers carefully.
We manage to share the financial stuff together although we specialize in different aspects of it. We decide on our asset allocation yearly. I do the cash flow and decide how much we can save this month, he keeps track of what to buy in our brokerage accounts each month depending on what we need. I do the book keeping for business and personal since it's the same application (although he knows his way around Accountedge a bit), and then also work out our estimated taxes. He does all the personal filing (I hate filing) and works more with the CPA. I've taken more interest in figuring out the sequence of withdrawals and taxable savings, as well as when and how to claim SS.
I used to not be interested in the investing side, leaving it to DH, but I found that he was more comfortable with more risk than me, as well as more active management. I think after last summer's drop he understands now that we need to balance our portfolio with more conservative holdings that can ride out a bad storm, and not be so enamored of managers. We're getting there, but it's a process.
So as you can see, you can divide up the tasks quite finely. Maybe he would like to work on the safe withdrawal rate, researching buckets, researching what tax bracket you'll be in and which pot to draw from. If he doesn't know spreadsheets, he could take an online course. The busier he is the less time he'll have to shop!
. I'll have to read it all.
or maybe not
