Hi, sunfluer and briony. Sorry, was busy. I've finished the game so let me see if I can help. Trying very hard to remember what happened.
Wing SymbolConcerning the wings symbols, you need to get a blacksmith to create the 'Wings of Valykyrie'. Go and 'Request for Smithing' then find the item in the 'L-Hand' section. Once you have that, equip an active member to be able to jump around whenever you see the wing symbol.
Spirit SwordAbout the Spirit sword, you need to get to Gabora Hill. If you don't see it on your teleporter options, you may access it through Twilight Forest. There is an exit at the East where you will jump up several times (You need the Wings, btw) and once you have Yozora smash the rocks, you will get to the Gabora Hill.
Once there, you need to kill the Ghosties to get Spirit Stones. You need at least 10 or 15 of these stones to be able to the Spirit Sword. Can't quite remember if you automatically get the skill or you have to meet a guy who's on the hill at the far East to show him the stones. Though I think you have to show him the stones.
Odd items here and thereDon't worry about these items in the beginning of the game. You will find members who are able to get these items later on. You will be allowed to access those areas again through the teleporter. Just make note of where those items are. I remember they were good items.
Just in case:
Mai - uses her whip to get you across chasms. Just stand exactly across the post and press 'R'. Mai's whip doesn't get
items, btw.
Cat's eye - has her boomerang that you can throw and get those out of reach items.
Any other questions, please feel free to post here. I will try my best to help.
Also read the books at the HQ, they have plenty of interesting info that helped me figure this game out. Or even comments by ppl give us clues.