Wow! 14 mo is really early to be interested in PL. That's really lucky! What kind of potty does he have? Have you tried him different potties? Bjorn has potties
that come in a smaller size and may be less intimidating to the younger toddler.
As for your second question, I have no real answer...but can totally relate. My DD is nearly 14 months and is also very clingy right now. A couple weeks ago, I felt like I was going to lose my mind, because it felt like she needed me as much as she did when she was a newborn again. It's gotten a little better, but she'll have her moments where little things set her off. I don't know if it's related, but her sleep schedule also is off. Every night is different, and her naps have not been consistent at all. I'm thinking about enforcing stronger routines to help.
Somewhere I've heard around this age they tend to be a lot more needful, because so much is going on developmentally (picking up words, learning to walk, exploring, etc...). Supposedly, around 16-18 months things are supposed to ease up.
Right now, I've been taking us out of the house as much as possible as distractions seem to help. Even just going outside in the yard has been a good thing. She has a Little Tikes playground I got off of CL that has been wonderful to play on. I'm hoping to get on old sandbox refilled this next weekend so she has another new big thing to play with.
If she's super clingy while I have to get stuff done, I pop her on my back in the ergo and wear her. Her size was getting a bit heavy for babywearing, but I found it's so much easier to wear her on my back now than the front. She seems happier there now, too. She can check more things out. We'll still encounter moments, though, she wants to be down and into things. She's such a busy little person right now!