The 1,000-year-old Boy

This is my second book from the author Ross Welford. (First book was “The kid who came from space”)

One quote / dialogue which could be the soul of this book is from Jack Mcgonagal, old friend of our protagonist, on the verge of death:
“I thank the Lord every day that I've been granted the gift of growing old. Because I would not want your life, Alfie, my friend. NOT IN A THOUSAND YEARS.” - Jack Mcgonagal

Questions I have are:
1) Why did Jasper willingly gave the life-pearl to Alfie (protagonist)?
2) Can a single life-pearl be used on more than one person/living creature? Because, at the end, Alfie used the last remaining life-pearl on himself. But, there is also Biffa (his cat). It would be better if he used the life-pearl on Biffa too, to regain mortality and stop being Neverdead.

Weird moments:
We seldom travelled, but, if we did, Mam would carefully unpick the seal and lift the tiny spheare out and swallow it for safekeeping. It would reappear about a day or so later, expelled in the manner dictated by nature. Glass - in case you did not know - is extremely resistent to almost all forms of chemical reaction, so the little ball was completely undamaged by stomach acids and other internal processes.