GZ Guide 10 is definitely pocketable, it is the smallest device of that kind on the market. You should be able to get about 80% of charge to your S6 from it (just make sure you've got Plus model). A cheaper option would be to get a Lithium battery based power bank. It will be much lighter, slimmer, and provide more energy (Guide 10 is around 2Ah, you can find a 10Ah LiPo for less than $20).

The Nomad 7 panel is the smallest they are offering and adequate enough for emergencies. It could be easily EDCed even in a small bag. Anker 8W panel looks interesting, but if you decide on GZ Guide 10, it's better to get the Nomad 7, as it has a special dedicated port for the most efficient charging of their Guide.

If you consider the LiPo bank, you can opt for one with a small solar panel on the side for pocket EDC. It's not very efficient, but I have one, and it can recharge its ~8Ah internal battery from about 20% left to 100% in 12 hours sitting in the full sun.

For Eneloops I would recommend visit your local costco and grab their new green box kit with 8 AAs and 4xAAAs. Their new 4xAA/AAA charger is great, as it can charge batteries individually now (1,2,3, or 4, mix AA/AAAs). You can definitely keep batteries inside forever, as that charger has a "smart" charging controller.