fwd weight distribution is a little different from rear wheel drive. Especially with a starlet, achieving 50/50 weight distribution is quite impossible and would seriously detrimentally affect the handling due to the design of the rear suspension. Correctly modified having a relatively front heavy fwd car can work just fine, just need to get the arse end to behave itself
I've been told people like british touring cars end up running 66/33 front to rear split, I would suspect my car would be pretty close to that at the moment. Bear in mind the 'stripped out' weight figures on the scales there was with an entirely standard engine bay, I subsequently removed quite a few bits and pieces from over the front axle, battery is lighter and mid mounted etc
starting with a levin you've got independant rear suspension and probably far less front heavy to begin with - i wouldn't consider the weight bias to be a huge concern. Move battery to the back, add in half cage, etc and it would end up being about right.
what I would definitely suggest is getting it weighed before and after. A) because then you'll know how you've done with the reduction measures and B) you'll know how the bias has shifted, based on the weight bias you can make decisions about things like swaybars, tire selection etc to address understeer
as close to neutral bias as is practical should be the goal, but even with fairly whack f/r bias less weight will always be better!