<i>There's apparently a trend among the younger generation to attach -ster to names (mostly one-syllable, I think), I guess as an affectionate form: jheemster, troyster, juanster, usw.</i>

No, but I like it. Most other (inflected) languages have a bunch of suffixes to use on people's names for hypocoristic reasons. Mostly diminuatives: e.g., Spanish José 'Joseph', Pepe 'Joe', Pepino 'Joey'; Italian Giacomo 'James', Giacomino 'Jim'; French Pierre 'Peter', Pierrot 'Pete'. You can see that this leads to longer names.