One problem regarding flying 'scale like', is with something like a Cub it would probably be the most boring of flights, how often do you see full size clubs flying like in your video ?. Most of the time they are just cruising around level.
So perhaps drop some of the 'scale like flying' until you get a fairly large scale multi engined model. There is nothing worse than seeing something like a B-17 or B-29 doing loops and flying inverted, at least in my opinion.
Do carry on having fun flying, that's what we are in the hobby for.
Something you could practice, and practice,...... though, is take-offs and landings. Getting those to look more professional does take a lot of hard work and concentration.
Take-off do not always need full throttle, or steep climb-outs. Likewise landings look so much better with a longish straight approach, before gently settling onto the main wheels, slightly before the tail wheel touches, (and I can assure you it's not easy to get right).
As for the use of rudder on a four channel model, it's usually used in coordination with aileron when doing flatter turns. Bank and yank is easy, nice flat turns isn't so. Rudder is also a must for doing stall turns.
Enjoy your smaller Cub, practice, practice, but will you really be happy flying a larger Sig version later, or could you be getting more fun from say a warbird, that is perhaps also capable of still looking scale(ish) doing aerobatics ?.