Sleight of hand?
Not really sleights in the true sense of the word...more like handling techniques.
However, you will need finger dexterity for some of the routines.
My recommendation...get some of the #19 bands, check out YouTube for some basic rubber band tricks and then determine how the level of arthritis in your fingers affects your ability to perform these types of moves.
The good news is that most are simple and easy to learn/do.
If you're comfortable with the basics, then you can come back and buy the download along with the Rainbow rubber bands.
Who knows...maybe you'll find enough 'freebie' tricks for your repertoire on YouTube and not need to purchase anything.
Sorry Penguin ;-)
One note...although they're 'just rubber bands', the rainbow colors add positively to most effects...consider getting some of those.
Best wishes...