I think usbourne DO specify that you can't work with another direct sales company - their concerns are probably about using their training to benefit another company, but in practice, how would they find out?
I work with Mini-Iq and we don't have restrictions. I think it is tough to do if you don't drive - books aren't light and parties are def the best way to make sales.
We do however sell maths-whizz via on-line subscription, so if you can get into the right circles with something like this , they can view demo's on line, and as long as they quote your reference you can earn a commission (even beter if they buy an annual sub). In the right circles (parents looking for extra tuition and prepared to pay for it - although not as much as a private tutor) it goes down brilliantly.
Back to driving - you could, of course, use taxis but these will eat into your earning so you would need to make sure you are earning the max bonusses each month to make it worthwhile.
You should think about how much you want to earn and then talk to whoever you are talking to about the companies about how this can be achieved.If you need to team build to earn what you are looking for then I think it's hard to do this for more than 1 company.
If you are just planning to earn from sales, you'll probably find that most companies pay you bonusses for selling over certain amounts each month., so for instance if you were to do 4 mini-iq parties and 4 pampered chef parties you may earn the basic commission on each (say 25%) but if you did say 8 mini-iq parties and so got to the max bonus (15%) you would get this on top of all the parties/sales you did so earning a greater percentage on each one.
Doing 2 seems to work ok for people doing low level of sales or having a main one, but the second as an extra - so do your Pampered chef or Mamatoto (I think this would work well with Mini-QIQ) as your main busness , but as you come across people who want educational stuff you can whip out your mini-iq catalogue samples and catalogue!
Hope this helps a bit and I'm happy to fill in anymore if you want!