Safety has to always be a priority when it comes to our kinks. There are general risks when it comes to water sports, like making sure the urine has no infections or bacteria in it. But taking it a step further to doing degradation in an uncontrolled environment, can be very dangerous. I would recommend if you want to explore these kinks, do it with someone you trust, somewhere you know that cleanliness is a priority. But aside from that, be kinky. And have fun.

There are many reasons why jumping into kinks that are more intense when you are brand new isn't a good idea. Kinks are fun, and they can lead to some incredible feel-good body chemicals. But when you are new to the scene and you don't have a solid foundation of trust, communication, knowledge, or a safety mindset, you are setting yourself up for major pains, hurts, harms, or trauma.  You are setting yourself up for the potential of getting sub-frenzy. You are walking into a situation without being informed of all the things that could go wrong or how to handle something that happens unexpectedly. You are not preparing for the deep emotional drops that can happen after intense scenes while having no support or knowledge to help you get through them. It's incredibly risky, not recommended, and could do way more harm than good. 

This one I can't really give advice on. It's honestly probably genetics or some kind of medical reasoning. If you've tried multiple impact areas and you are struggling with getting bruises, then I'd say that is what's going on.

This is essentially easy to do but can be hard when actually doing it. So, the best way to ensure someone has your best interest in mind, or has positive intentions when it comes to interacting with you in a BDSM dynamic is to vet them. Vetting (I wrote an article on it, you should check it out) is getting to know someone and going over questions with them that you ask them BEFORE you agree to start into any type of Kink relationship with them. Is vetting all you can do? No. Take your time and get to know them. Keep an eye out for red flags. 1 red flag isn't always an issue but if red flags start to pile up, then it's best to remove yourself from interacting with that person. Now, will all of this prep work make it to where you are guaranteed to never get hurt by someone else? No, unfortunately not, but it will make your chances for a safe relationship more likely because you took your time before you started your dynamic. When it comes down to it. Take your time. Be cautious, get to know the person. Learn about them, see if their style fits your needs. And if they aren't willing to wait or get to know you, if they don't want to learn about you before they start, then they likely aren't looking for a quality dynamic and are just looking for a quick fix or someone they can take advantage of.

I have personally seen Ratan and Bamboo used for impact play. I've seen people use really flexible/vine type switches and I've been also seen thicker, non-flexible switches or canes used too. As far as what's the best type of tree, that will be a personal preference. Go out, grab a few, and test them on yourself. See how they feel in the hand, and see if they are durable or break easily. Kinky research is always a fun time. As a general rule, the thinner the implement, the more stingy and whippy it will be. But don't limit your options too much. There are plenty of items that can be used as a switch that isn't wood. Phone or electrical cords, rubber bands, or hangers can all be used for a fun time too.