It indeed needs working out, and your remarks help a lot.
1. That's one of the key objections I could expect. If you agree to see a democratic government as a opportunistic political mix of parties and programs, that would be half your answer to your first remark. Most government leaders can't do more than try and press through a part of some of the election points of their particular party while compromising on all the rest. So I'd think not that many world-view unilateral programs get implemented anyway.
As for your last sentence: that is actually the core of what i'm aiming at. We vote for our particular political program / party, but at present it stops there. Usually we then see our politicians swagger in parliament doing exactly the opposite of why we put them there. Now, if we can take away their power to do that by detailing their budget, it would make for a very convincing extra stimulus for the political activities we, collectively, want them to perform.
There's not a big moral difference between voting for one party, meaning you endorse them to execute their program, and allocating means to the eventual government, meaning you endorse it to work for you on a number of particular fields.
2. The idea is: Vote for party XYZ -> Formation of government XYZ with program ABC -> allocation of means by taxpayer to ABC.
Since each voter still has one vote, the more numerous lower classes can always endorse a strong lowerclass sympathetic government who can focus on mostly lowerclass aimed program points. Upperclass taxpayers would allocate their tax to those program points as well, if the government is smart enough to structure them thusly that they don't particularly disadvantage the upperclass.
I don't expect a dystopian hardline society, if that's what you're driving at. For example most political parties have some sort of humanitarian and social part in their program. So that will be mirrored in the eventual (coalition) government.
How many CEO's and millionaires are there, and what percentage of the tax do they contribue? I don't know, but I'm postive the 'regular' (non-millionaire) upper, middle and lower class make for 99% of the taxes. I figure millionaires park their capital offshore anyway.
3. A careful government has reserves built up to do emergency programs. Perhaps the system can be set up as such that a program like that would draw available funds from the particular field / fields it intends to rescue. Bailing out broke banks would be harder, or perhaps impossible, since it can count on little sympathy. I don't have the answer to that. Perhaps the end result would be less irresponsible banks that conduct a sound financial policy instead of raking in bonuses and building on air? Contrary to other subsectors, of our economy, that do have sympathy, such as green energy and the likes if an energy crisis would occur.
4. That's a practical working out problem. You could make it optional to do. If you don't want to go trough the trouble you could always opt a 'default division', leaving it to the government in office to attribute where they want it to execute their program.
One person acting alone will usually act in it's best interest, whereas masses are dumb and will be guided like sheep. I think it's interesting to think about the result of a collective sum of the smart individual -financial- decisions. Perhaps it would be like a mitigated invisble hand transposed to the political scene? The sum of self-interest money allocations, restrained by the vestiges of the governments program that is in turn composed out of a mix of the programs of the democratically elected parties...
☑ Saddam Hussein ☑ Osama Bin Laden ☐ Justin Bieber