Battery life of new iPad

You should have no need to fully discharge your iPad battery - in fact, for Li-ion batteries, fully depleting the battery can be irreversibly damaged by deep discharge. There is no benefit to be gained in fully discharging - or deep cycling - the iPad’s Li-ion battery.

See >>> Batteries - Maximising Performance - Apple

All batteries have a finite service life - with a limited number of charge/discharge cycles. Every battery charge cycle diminishes the available battery capacity by a tiny amount; this effect is cumulative - and causes the battery to slowly lose capacity over its usable life. It therefore follows that minimising battery use by using external power, where available, will prolong the overall battery lifespan. 

Apple quote expected iPad battery capacity to be 80% of the initial total battery capacity (when new) after 1000 full charging cycles.

A full charge cycle is any combination of charging that totals 100%. Unlike older battery chemistries, fully discharging and recharging is not beneficial - but instead increases the risk of the Li-ion battery being left in a discharged state - leading to unrecoverable battery damage (a phenomenon known as “deep discharge”).

No, that’s not required. You can if you want but it won’t affect anything. Have a nice day!