I didn't add more than a few keywords due to the fact I didn't want the post to be one big bad spoiler tag, instead, I opted for keywords and posted people could PM me for more detailed instructions.

I'll answer your questions below and add some links (quests are involved), however, as a general warning, the following will contain spoilers and I won't filter them out individually.

Sentinel Island part:


Leggings: From the trader in the camp around the ships. --- This means the trader, namely Sam who's close to the shipwreck camp on Sentinel island. His exact location can be found here: http://guides.gamepressure.com/divinityiiegodraconis/guide.asp?ID=8166 (nr. 14)
Mr. Shiny is acquired by doing the Hermit's quest. It is a key (Mr. Shiny) which opens the chest on the same map. (S1)


Orobas Fjords part:


The corpse of Jack Bolton is located at the Orobas Fjords as is Gwynn : http://guides.gamepressure.com/divinityiiegodraconis/guide.asp?ID=8184 (nr. 11 and 15)


Thanks for pointing out the chest/legs bit, I missed that, I'll update the post right away. I haven't updated/confirmed Phyonix'find yet due to the fact I'm exploring every single bit of the maps in order to find more goodies and I didn't make a save game at that stage the first time I played trough it.

Hope this helped,

- Merdarion