Why wouldn't Scrooge and Beakley trust Webby and her skills when we the audience know that she has considerable skills? Heck, Beakley trained her granddaughter for this. Simple: character interaction. Beakley knows Webby is clever enough to capture Ma Beagle, but hasn't actually seen her in a combative situation. Plus, she has the whole "little overprotective" stuff from the pilot. And Scrooge only ever saw her in the context of the group getting surprised or working towards a new goal. So while he might know her commitment, he doesn't really know her training yet.
Since it is more or less confirmed the Gummiberry Juice runs on the same rules as in Adventures of the Gummi Bears, with animals bouncing like rubber and humans/humanoids getting Super Strength, then why don't any of the characters here get Super Strength if this show treats them as if they were human? Because even though anthropomorphic, they are still animals at their core much like the Gummi Bears, and thus lack a humanoid physiology. As for creatures like the ogres in Adventures of The Gummi Bears, even if they are beast-like, their physiology is close enough to qualify them as humanoid, thus they get super strength.
Beakley's agent code number, 22, makes reference to her Alliterative Name, Bentina Beakley, as 'B' is the alphabet's second letter.
It's also a reference to British bingo lingo. The call for 22 is "two little ducks".