First of all, it's not an unlimited resource; the Druid can only wild shape twice per short rest, limiting the amount of poison the Rogue can attempt to harvest and by RAW:
DMG p.258
Serpent Venom (Injury). This poison must be harvested from a dead or incapacitated poisonous snake.
Unless the Druid can retain his form after dying, the Rogue won't be able to farm Druid snake venom. Furthermore, the DMG says that harvesting poison requires a check:
DMG p.258
Crafting and Harvesting Poison
The creature must be incapacitated or dead, and the harvesting requires 1d6 minutes followed by a DC 20 Intelligence (Nature) check.
It goes on about how to add proficiency to it and what happens on a failure but the DMG at least says that harvesting parts from creatures is not an easy task (DC 20 is hard, after all)
The point I'm trying to make is that you should allow your players to do clever things but limit the powergamey-ness to a minimum level that doesn't completely break your game. How you do this is up to you, I personally find that, at my table, at least, that doing the "yes, but..." approach to GMing maximizes the fun. "Yes, but you have to make a check to see if you can get enough venom for a single dose (this is important, you can get the vial half full but that won't cut it!). The druid can help you by giving you Advantage on the check, but it's not automatic." Being flexible like this allows your PCs to at least attempt the thing they really wanna do, and fosters a fun game.
As for other possible attempts to exploit "infinite" things, allow and disallow at your own discretion. A good tip for this is to think about how overpowered it would be to allow it.
Take your infinite arrow feathers example, by pulling the feathers off the wild shaped druid (ouch!), he is able to save a whopping 1 GP (What a bargain!). Consequences may or may not exist, depending on the kind of game you're playing but I would personally rule that once the druid reverts, he finds that he lost some of his hair.
If the form you take with Wild Shape has Darkvision, you will have Darkvision while Wild Shaped into that form.
The section of Wild Shape you reference in your question is about keeping features from your normal form while in your Wild Shape form, and includes an exception for special senses such as Darkvision.
The general rule for gaining features from your new form is this:
Your
game
statistics
are
replaced
by
the
statistics
of
the
beast, [...]
The Monster Manual has a long section on monster statistics, listing off a whole bunch of things - including senses (page 9). So under this rule, while in Wild Shape, the senses of your new form replace the senses of your normal form. And unlike the previously mentioned rule about features from your original form, Wild Shape has no exceptions for senses.
Best Answer
No.
When a druid assumes a form, he takes on all the statistics block of an average member of that species. Your barbarian/druid physical abilities only work in the original form.
From the SRD: