First of all, Jerry, I like the way you think.
I understand that a PokeTranslator might not be optimal/ has limited usage in a Pokemon-game such as PU. I also agree on some of the comments you've made. Below, I'll try to elaborate on some a bit more with what I had in mind, and combine it with some of your ideas.
I think we agree on the fact that there could be a Professor X (let's say Professor Steran) in the game, who is trying to create a PokeTranslator. Since he's the timid and shy kind of guy, not the best in communicating with others and definitely not adventurous, he has a hard time finding all the materials he needed. He was able to obtain some materials for the PokeTranslator from the local PokeMart (or possibly a local science store*), but that wasn't enough to finish the PokeTranslator. So he sets you, an adventurous boy/girl, on a quest to obtain the materials he still needs. These could for example be
Chain 11. a tire and some screws from the bicycle store;
--- For example, the professor notices that his machine keeps falling apart and asks you for supplies to help him keeping his machine in one piece.
2. another PokeDex from the starting Professor;
--- Professor Steran needs this to be able to imitate Pokemon speech.
3. a berry pouch/coin case/bag
--- This would make it possible to carry the PokeTranslator (as a key item, eg).
4. a Pokedoll
--- The Pokedoll will become the test subject, to make sure that no Pokemon will be harmed.
Once you've completed the chain, Professor Steran becomes so excited that he takes the machine and runs off (he mumbles something about the beach where Pokemon are often stranded and which would make for an excellent opportunity to test the machine).
Chain 2You see the professor lying down on the beach, trying to keep in his tears. He doesn't want you to know that he was actually crying. After all his trouble, and actually being able to communicate with Pokemon. He says something like:
... Sniff ...
I ...
I finally...
I finally managed to finish my PokeTranslator...
Sniff...
And now Team BadGuys has taken it from me.
I dont know what to do.
Sniff...
...
Could you get it back for me?
Sniff...
Please?
If you've regained it, could you bring it back to me in my lab?
(Professor Steran walks slowly back to his lab. He does not want anyone else to see him crying.)
* Insert battles with the local Team BadGuy to regain the PokeTranslator.
Once the PokeTranslator is regained, the player goes back to Professor Steran.
Chain 3He feels better again and sets you out on a quest to gather data with the PokeTranslator. He says that he saw a Seel on the beach, but he's afraid to go to the beach because of what happened, so he asks you to do it. Once your on the beach, you see the that Seel the Professor was talking about, is getting beaten up by a Team BadGuy person who was still lingering aroud. After you battle him and win, you turn to the Seel with the PokeTranslator.
--- 2 options:
* either it works and the Seel tells with his last strength (fainting, dying, choice is up to the developers. Dying would give it a more dramatic touch, but since PU should be for everyone and Pokemon dying is actually quite not-done overall, I suppose fainted is probably the better option for PU) if you could tell Desha in the local city that he was happy she was his trainer and if you could bring him to her, but a giant tidal wave causes the machine to short circuit so that the poketranslator becomes useless
or * the machine didn't work at all and the machines just made strange noise as a side effect of the sea noice that interrupts with the machine that were mistaken to be translated pokemon speech by the excited but social isolated Professor Steran You still understand that the Seel needs medical help and so you bring him to the Pokemon Center. After you let him be healed, a girl walks (runs) into the PokeCenter:
'Seel, Seel...
Where is my Seel?
I've heared that a Seel was brought in and hoped it was my missing Seel.
I haven't seen him in days.
My poor Seel.
And with all those Team BadGuys around...
I hope he's alright!'
...
'Oh, there you are.
I'm so happy you're alright!
Thanks for taking care of him, <Player's name>!
Here's something that might be useful for you.
I know it helped me a lot!'
* You've obtained the HM Surf. (+1 HM SURF)
When you head back with the (remains of) the Poke Translator to Professor Steran:
Oh, there you are.
How did it work?
*option 1: (the excitement and social isolated professor)
...
Oh...
...
Guess it wasn't done afterall.
Thanks for your work though!
Perhaps I should give you something...
Yes... no... maybe...
Would you like a car (or insert random other non-usable/wantable object)?
Oh, no driver's licence you say?
...
Than how about a ticket to sail with the Tidal Trip?
I won it with a quiz, but I'm afraid to go myself.
I'm not such a people person you see...
I hope you'll have a nice trip.
Guess it's time to get back to work.
While you walk away, you hear the Professor mumbling, 'someday, people will know me, Professor Steran, as the Professor who've made the PokeTranslator!'
*option 2: (the machine worked but a tidal wave
...
Oh...
...
Guess it wasn't made out of tough enough materials afterall.
I know I should've used stronger ones, but they would definitely intervene with the machine...
Thanks for your work though!
Perhaps I should give you something...
Yes... no... maybe...
Would you like a car (or insert random other non-usable/wantable object)?
Oh, no driver's licence you say?
...
Than how about a ticket to sail with the Tidal Trip?
I won it with a quiz, but I'm afraid to go myself.
I'm not such a people person you see...
I hope you'll have a nice trip.
Guess it's time to get back to work.
While you walk away, you hear the Professor mumbling, 'someday, people will know me, Professor Steran, as the Professor who've made the PokeTranslator!'
--- my preference would be the first option, where the PokeTranslator actually works, though be it for a really short amount of time.
* A local science store could also be a main point for other science related quests, definitely if it would be the only science store in PU.
And about aiding Nurse Joy, it's always possible to set u p a double chain-quest where
1. gather your own healing kit through several quests (healing kit -> key item)
2. applying bandages/small healing to pokemon (near/ in pokecenters) under supervision of nurse joy
3. get a feature where you can put bandages/ small heals with healing kit and obtain a title such as Nurse's Apprentice (or something like that).
I'll work on this one later on.
ps. I'd still think it would be awesome if there would be some kind of way to get behind the scenes, in the back of the PokeCenter, where all the Pokemon get healed.
Edit:
Perhaps this topic should be translocated to the quest-section.