Easy ways hard ways everybody has their way.i just use Medium spray glue and then use a mix of acetone and mineral spirits to make the pattern fall off!
Kids like to,be able to,do,things on there own and getting a piece to fit will make them happy.now a 4 year old just loves a shovel and a bucket to put sand in and tote it some where .They love being free to do something like that!
When i was doing airbrush the Germans had a magazine much better than the American one,i think your going to find the same is true for the scroll saw one too!
My take on the pinned blade is that's what was used first and then the straight blades came out.In over 4000 projects i've done i can't remember using a pinned blade.
Lots of good questions ! Most important one is keeping the table and blade square to,each other .Other wise the pieces won't go together or come apart!