Tonka, you show signs of the same attitude as the more benevolent and helpful captains who have commented here. It would be reckless to allow FOs completely "off-leash" - the captain is always responsible and no-one is suggesting we don't supervise them and help out when they reach their personal boundaries, except Narrow anyway. As a new captain, your limits and your confidence have yet to reach their potential, and you are still learning the skill of assessing your FOs' limits and predicting their errors, so are wise to be a little more restrictive with them than the experienced captains, but you still see the benefits of letting them handle progessively harder situations with less and less guidance to help them develop their command skills. Good for you.
Line training of cadets is just to a minimum standard that they should be of help, not a liability. It's like getting your driving licence - it's a licence to learn. The only place that FOs gain useful experience is on the line; simulator exercises are great for learning basic profiles and some stick and rudder basics, but they are far too limited to teach airmanship or handling skills in bad weather. They can only learn that on the line, and only with captains willing to help them in that learning. I learnt far more from line shags than trainers, and I endeavour to pass on as much of that knowledge, acquired over generations, as I can. I would hope to see all captains do so, but sadly this is not the case, as demonstrated here.