Lack of boundaries is true with Neptune but on the upside would imagination work if we were stuck within boundaries? Connections to personal planets is difficult, because it's hard to tell how much is it realistic to expect from anything related without losing your enthusiasm or hope for life itself.
Correct me if I'm mistaken (I'll own my Neptune here) but hope and enthusiasm for life aren't entirely water qualities but also fire, latter just being more active and less sensitive, therefore perhaps coming off as less daydreamy... but then fire people can be equally daydreamy about other persons feelings, therefore assuming they're being loved if someone simply submits to them due to being overwhelmed. Think about Pisces and Aries in a relationship; Pisces wants an adventure and being loved but Aries isn't giving it the way Pisces would feel comfortable as themselves, but Pisces finds an excuse to see how/why Aries's way of showing love is still true, even if not on Pisces's terms.
Then Pisces finally has had enough as Aries might have walked over Pisces's boundaries... for example if Aries became violent or abusive towards Pisces and was dragged into court, Aries would just say: "I thought Pisces loved me and enjoyed because they stayed with me!" while a more sensitive person could've spotted Pisces was internally screaming for help. And pardon if I'm excessively stereotyping the signs in someone elses taste, not saying "all Aries and Pisces are like this".
One question I've been curious about, how to deal with Neptune if it's strong in your chart. I can say I avoid human relationships just due to fear of ending up into similar position as the dear Pisces in my example (yet I'm not a Pisces, 12th hosue south node though), but I'm constantly lacking energy which comes so easily for loud, aggressive and selfish Aries type people, I don't know how to do anything without being overwhelmed or having to rely on someone else when things get rough. It *****.