Sensored vs. sensorless motors and ESCs. Perhaps a good idea to stick with matching types. Yes some sensored ESCs can run sensorless motors, but some can't. And most sensorless ESCs will run sensored motors, but sometimes not all that well. If considering crossing types suggest doing some research before spending.

Some combinations of servos, ESC, and radios can present a challenge, not a deal breaker but something I think worth mentioning. Some high powered servos, notably some Savox and other Tricore based ones, occasionally other high powered models, have very high amp requirements and don't work so well in certain combinations, can lead to radio brownouts. Some ESCs are known to have weaker BEC circuits than some, Castle being one, I suspect Tekin RS series are slightly weaker than most, possibly others, can have trouble maintaining voltage under the high servo load. Budget Spektrum receivers are more susceptible than most to brown out issues in these combinations, but it also occasionally causes issues with other brands. A fairly inexpensive Glitch Buster or Stutter Stopper capacitor on the receiver frequently solves the issue, sometimes an external BEC is needed.

Absolutely. Yes, most lipo chargers can charge most RC lipo batteries, but if you have a larger 1/8 electric or a monster truck that uses a 4S to 6S (or larger) lipo, the charge times can be very long with a generic 40 to 50 watt charger. (For some of us a 50 watt charger is too slow on even a 2S )