As a former volunteer who also works in mh, yabu.
Firstly, it's a huge regional organisation they have to have some parity over what volunteers are able to do and direction for new or infrequent or inexperienced volunteers. This protects callers from inappropriate 'advice' and volunteers making it about them by oversharing personal info and protects volunteers from becoming too emotionally embroiled in something that might hit close to home. It also protects the organisation from volunteers saying the wrong thing. A lot of the info you're talking about is really prompts so if a volunteer gets stuck on a call and isn't sure what to say next, they have some ideas that might help them.
Secondly, I fully support the idea of self determination, I had a loved one who passed away by suicide and I hate that, that must have been the most lonely moment in their life because they knew if they told someone, they'd try to stop them. So they were completely alone. At the very least it means that if someone is going to kill themselves and are absolutely resolved, they don't need to be alone in their final moments. It also means if they do change their mind there is someone there who's able to get help, if calls were traced or info was required people would give false info wasting emergency services time, or they just wouldn't call at all and they'd do what they intended alone.
Thirdly, the techniques you're talking about reflecting and clarifying are basic counselling skills. So since all the volunteers are trained to a very basic standard compared to mental health provision, why would you expect them to do more than basic counselling/ listening skills. You might have experience in that field but the majority of volunteers won't.
Also, as a listener you've no idea of the full context of the callers life or mental state, even if they're a regular caller. It's not appropriate to assume you're the best placed person to give advice or that you have the full picture to do so. By reflecting and clarifying what you're trying to do is help the caller sift through their own thoughts, come to their own decision or resolution and if they can't- because some situations just can't be resolved or fixed they're just really hard, you're meant to just be there as a listening ear and a bit of compassion and empathy. You obviously can ask questions like who else have you talked to about this, who in your life could you talk to etc etc so you can help the person reflect on who would they tell that could help them and what would make that more doable for them without saying - oh you need to tell your gp or go to a and e etc. That shuts conversation down and a lot of people will have already tried those avenues and be very frustrated with the lack of help they feel they got.
@Welshpancake "knew how to hold me when I was in deep crisis". I think that's a beautiful way to put it actually. You're only there to hold space for someone who's in a painful place, not to try and 'fix' it for them.
Op, I'd recommend going back to your training lead and working through this with them because I don't think you're grasping the purpose of what you're there to do.