Jason
You are asking the classic questions car designers have been mulling over for time immemorial. I cannot answer your questions but I know a man who can, dependant on where you live that is.
I ask the question are you a closet designer or a kit builder, it sounds like you want to learn to design and then test but you are starting possibly in the wrong place if you want real results. They do degree courses in Motor Sport Car Design and perhaps you have missed out on doing this as an occupation I don't know.
Are you considering 'roll centres' (
http://performancetrends.com/rc.htm) and braking effects in your design?
If I read your questions correctly you want to build in flexibility to your design to obtain the best result long term, getting the pick-up points in the right place is crucial I agree, saves a lot of hacking and welding later.
In the end its the weight that the tyre exerts on the 'road' that will determine the characteristics of your proposals for supporting it.
The other thing to remember is what you want to use it for off-road or F1, the extremes indicate the balance you are trying to achieve no one design will achieve all you desire that's why rally car designers have different designs for the same car dependant on where they are racing, gravel tracks, tarmac or grass.
You run the risk of designing something that when made and fitted does not actually do that you thought it would and that will cost time like a good'en and cash you may not want to part with.
I could understand if you had a test car to play with, on which you could modify fit and test for quicker turn round of design changes, anything else will sap your tenacity and enthusiasm in quick time.
I am not trying to put you off, just offer some insight to what other have done before you.
I think you have two options:-
Design on paper and submit for evaluation via tried and tested software evaluation tools. These tools will tell you how your design will perform under all dynamic conditions and even tell you what under-steer you will encounter on a specific corner of any race track in the UK.
The second option is to talk over your idea's with an experienced designer who can tell you what will happen based on 30 years experience in designing building and testing just exactly what you are doing yourself.
Drop me a PM if you want to know the contact details for Dave Gallop of Track Developments.
If you can visit Dave he has models that demonstrate the effects of set up and design errors, he can tell you what will work under different conditions and he can apply your design, if you choose to pay the test fees, to a software evaluation tool before you spend time and money on something that will not work.
He has supported race teams, he has designed (and is currently designing) suspension systems and knows what will and will not work. He can build a test model and can improve on your idea's if you choose to accept his experience.
This will save you time and money and get you someone to talk too who you can trust, without costing you a fortune.