How's this for a start:
1) Permanent hierarchy must be avoided. Ideally the process will be mechanical at the top, i.e., the planning process will follow a set of pre-defined rules which must be adhered to in order to take the human factor (and thus authority) out of the planning process. That is, local groups provide inputs as to what they want and so forth, but the output (the plan itself) is generated based on pre-defined rules. There might be multiple iterations before a final plan is reached. The danger is having an elite group dominate the planning process with the attendant inequalities in income, prestige, and social position which will result.
2) Planning should be as decentralized as possible. Small groups and communities should be given as much latitude as possible. Of course they will have to operate under some constraints, but within those constraints there should be wide freedom to choose how to tailor their economic activity. There should be little or no orders from the top of the "You will get X and like it" variety.
3) everyone should have roughly equal input into the planning process
Some of the things you address are impossible to answer without going through the planning process itself. For example, how many resources to devote to health care depends on the general level of health and the relative importance people place on health care vs. other possible uses of the same resources.
Brett