So I've decided to be just friends with this guy...?

I think it's fine to continue texting him like you do, if you can handle it. I was in a situation extremely similar and kept it up and just ended up getting hurt because I thought I could just hook up with him and I wouldn't get more attached or thought he'd change his mind. If you want to stay friends go for it, but I'd keep it very clear to yourself and him that it's just friends and not blur the boundaries at all or put yourselves in situations where they could be blurred.