What does food do for me?

From what I read, I shouldn't even invest in food at all or research the techs for food, because I am going to use essence instead?

Also, do I have to be at war to leech? Can I leech minors? My leechers have no offense, so I am not sure how I am going to get my second system until I research proper combat ships. How do I start off?

food will still grow the vodyani (i almost exclusively play them by now), but it is not really worth it, if you are good with essence farming.

-you do not have to be at war to leech; however, other races may close their borders or attack your leech ships in orbit if they are not protected by a fleet of yours and you are in a cold war

-you can leech from minor races, however their systems will spawn pirates so you need a fleet protecting your leechers

-if you leech from a minor race you only need a max of 4 leecher ships as the minor races' growth will turn negative and you have to wait a few to turns with leeching once they reach 0 population and you can start leeching if they get 1 population again.

i usually play like this:

-first turn build drone networks

-research xenolinguistics for the xeno-industrial infrastructure (this should finish the same turn as drone networks)

-build xeno-industrial infrastructure

-make a new ship template with the Goyam-class (scout) with two missiles (or the highest dps long range weapon, if you find better ones during exploring), 1 shield and an engine ==> build 4 of them assign them to a fleet with your hero (he can govern your starting ark/system until then to gain experience)

-in the mean time explore your system with your two starting ships, be aware that your race quest will spawn two weak pirate fleets in two systems that don't move (so just retreat if they spawn on top of your exploring ships)

-if you find a nearby system with better planets, move your ark

-move the leecher and your 5 ship fleet (4 combat scouts + hero) to the minor race in your system and start leeching

-build 3 more leechers and move them to the minor system as well

-you now gain enough essence to build a few arks

-research priority after xenolinguistics is galactic commodities (to sell stuff to keep your dust positive) and multi-threat management

-sort out your dust income with those two techs and buildings

-upgrade your arks with only science modules ("all must study"), you should get 3-5 arks

-research adaptive colonies (science and exploration IV)

-upgrade all arks with "all must provide II" modules, you now can stop harvesting essence with leechers and declare war on the minor race and take their system, the arks will provide all the essence you need from now on

-research/build anything you want

other tips:

-vodyani heroes are great fleet support heroes if you go for energy weapons, i.e. long range lasers (never go for beam, you rarely make it into the melee phase)

-if the minor system is very close to your starting system, you can skip the engine on the Goyam-class combat ships and add essence harvesting modules. this lets you skip one leecher ship

-you can ignore peace treaty demands and be in an endless war by using the "mass gratification" law

-vodyani have the easiest way to gain manpower with the chain gang program "N-Way fusion" once you have "all must provide II" modules

-the biggest weakness of vodyani in the mid to late game is strategic resource generation as you do not get planet specializations like other races that can increase the income from strategic deposits.