I'm sure many people are better qualified than me, but here goes:-
1)Trucks are rated by lifting capacity (among other things) so a 1 tonne truck will lift 1 tonne irrespective of it's power system. It may however vary in overall size.

2) Charge will vary according to battery size and type and hours of daily use. But probably 6 hours? The norm is to have spare batteries on charge to swap over in 24 hour operations.

3) Electric trucks do create waste but not in your workspace - they use electricity which is provided from clean, or dirty, power stations depending where you live.

Many people using this site are real experts and can advise you in detail. I have attempted to help but posting more particular questions either on this site or direct to a dealer rep would be more use to you.