With regards to words ending 'PS' my advice is to just havea go at tackling it. keep on at it until you eventually nail it.. And TRUST ME - if you persist long enough you will eventually nail it. Maybe in 6 weeks or 4 months.. DONT expect it to happen over night. Liken it to going to the gym, and not being able to lift the heaviest weights until you've built yourself up on the lighter weights, then the medium weights for a few months before hand. . .
Some so called vents advise you to avoid using certain words or sounds that are difficult to pronounce - in my opinion, that advice is a cobblers. Just have a go, and keep on trying. You WILL eventually crack it.
Regarding scripts. I always write my own. My scripts suit my characters. I used to look for script books, but found nothing that suited my style, or in fact, anything which I ever felt happy with putting in my own show. I now have SO many scripts I am spoiled for choice as which to perform in the shows I do. . . Maybe, one day, I should publish my scripts?
As to how to write them? Well, I guess that's a topic that needs many minutes to explore.. I think we all have our own unique styles.
I base mine on my character. Having a clearly defined character for your puppet is essential, then you can develop material based on how your character would behave/react/interact etc.
If you had a mean character, you could explore the possiblities of trying to get him to share his sweets with the audience. He wont want to because he's mean. How will he react? . . . Its that old cliche of stimulus/response. Let your imagination run free. Just write all the ideas that come into your head. DONT edit or try to make sense of them. Just let them all flow out in a brain storming kind of way... Then, the next day, Look at each idea in turn and see how you can flesh it out, based on how your character would genuinely react. AND how YOU and Your OWN personality would contrast this.