Hello from Athens, Greece!
It's all matter of personal taste about the feel, BUT if you want to master the organ playing technic you have to use a waterfall action keyboard. I'm not a guru and not eve a good organ/piano player, but you will find out that playing the organ passages, glissandos, open-hand percussion and related styles is not something you can do with ease in a hammer/piano action keyboard, because of the fast action keyboard that is needed and you will probably hurt your hands/fingers if you try to do some classic hammond playing.
When comes to bass pedals, it's another planet, so you will have to study a lot so as to think simultaneously 3 things to play (left, right hand, foot bass), so I can't tell a lot about. I've tried some times with a bass pedal but I didn't like it because I had to sacrifice a lot of thinking, while I'm not a pro player, even with only the two hands. Bass on the lefthand is the standard if you don't have bass pedals or real bass player. If you do, the left hand is usually combying the chords while the right will be available for melodies or solos.
The ES100 is an excellent piano action for the price, I've recently bought it for home studying, but when it comes to organ, I always prefer playing and recording a semi or synth action controller/keyboard like my semi Kurzweil sp4-7 synth or a synth-action Studiologic SL161 controller.
For a live use, you can do the basics with the ES100 with an organ sound, but for studying I would avoid lot of hours playing.
You can buy a good 61keys midi controller for organ just for some bucks. The cheapest one for me would be the M-audio Oxygen 61 Mk4, which also has 9 faders for hammond drawbars control or a swissonic, but I would definitely avoid the keystation, Nektar, alesis cause of the semi piano-like keys that may lead to hurting your hands/finger if doing glissandos.
For a free organ VSTs, you can read the following review:http://blog.wavosaur.com/7-free-vsts-for-hammond-b3-emulation/
I can recommend the AZR3 as a good one, even comparing it with the NI B4 or the NI Vintage Organs that costs a lot of money.
I hope I have guidance you with the basics, I'm available for any further questions and conversation and I'm sorry for my poor English. ;-)