as many people already stated,lipo use in the electric car world is not popular and are not legal in all race sanctioned organisations.
looking at nimh though the best features would to have;
as someone else said diffrent amp settings for 3 or more stages
2]temperature cut off.
3charge amps upto 10amps.
4]discharge upto 30amps at least.[not many charges have this and will make a big difference.3amp discharge will never be used]
5]motor run would also be gud incl. amp draw,rpm.
maybe you wil please more people if you had a different charger for different classes.
also this would make individual charges cheaper for the customer.
people may buy a charger and may not use 50% of the functions because there for a different class.
i think its also good that a company outside of rc is trying to get in.
more competion and may even teach other established companys a lesson or two.
good luck with your 'new' venture.