Lower-leveled spells can be cast from the same list
Essentially, the Shaman gains 1 spell slot per level that can be used to cast any spell of that level or lower found on their spirit lists.
A hypothetical Level 3 Shaman could use their 1st-level Spirit Magic spell slot to cast the 1st-level spell granted by their Spirit, and then use the second level spell slot to cast the 1st-level spell or the 2nd-level spell granted by their Spirit.
At 4th level and beyond the Shaman can access the list of one other Spirit, doubling the number of spells to select from when spontaneously casting.
1) Yes, you dont need to have 9th level spell slots to use spell perfection, thats why some 6-level casters take it. You simply make your own "perfect" version of said spell.
2) When a text says "you have the ability to cast" it means you must have it as a spell known or be able to memorize it, items that allow casting it will not meet the requeriments. I believe that recent FAQ's even ruled out spell-like abilities obtained from traits or racial abilities.
With that out of the way, No, because the wand has no requeriment to use it, the spell does, only half-elves can cast paragon surge, due to Range: Personal (half-elf only). UMD would allow you to use a Paragon Surge wand without being one of the classes that can cast it:
alchemist 3, bloodrager 3, cleric 3, magus 4, paladin 4, sorcerer/wizard 3, witch 3
The wand has no requeriment unless the creator choose to make it require a half-elf to use (which would lower the item cost), or enchanted the item (not a wand, but this happens to weapons, armors and wondrous items fairly often) with a special ability that requires a certain class or race.
A forgiving GM could even allow you to emulate a race to obtain a special ability from an item that only works for a certain race/class, like the Belt of Dwarvenkind. Otherwise that specific use of UMD will not see much use.
3) If your character is an half-elf, you wouldnt need UMD at all and the answer would be: Yes, you can change the spell from spell perfection every day, on each cast of Paragon Surge, as long you also know three other metamagical feats.
Best Answer
No
While Echoing Spell doesn't explicitly call itself out, I'd certainly consider it an effect that allows re-casting and as such can't be re-applied.
So while Spell Perfection may allow you to add a metamagic feat to the second cast, it can't be a second (or third, or fourth...) Echoing Spell because Echoing Spell forbids it.