I think you're doing great. I don't think there's any problem with using the word no. The problem is if you say no to everything.
I have a fear that my toddler's only childhood memories of me will be me not letting her do things and constantly telling her no. I let her do lots of stuff, but I just let her at it. I don't say "Yes, honey, you can do that" to her all day long. She only hears "No". Oh well.
I think "no" is appropriate when things are absolutely non-negotiable. If they are going to damage something, hurt themselves or someone else, or get in a dangerous situation. 10 months is too young for them to understand why something is dangerous, so just say no, and remove them from the situation. Distractions are the way to go at this point.
I also let my daughter mess things up, even though I don't like it, if it really is no big deal. I just think it's important that you have the child help you clean it up later. I don't constantly walk behind my daughter cleaning up her messes, so my house usually doesn't look great. However, before naptime and before bedtime part of our routine is to pick up the books and toys off her floor. That way she sees me cleaning and helps me on a daily basis.
As for explaining things, kids understand more than we think they do. If you can keep the explanation short (just a few words) then I think you should keep it up.
It sounds to me like you're a great mom. Good luck.