To answer your question directly, here are a few CLI editors:
As far as I know they won't show syntax errors as you type or even on save, you won't get any (semi)auto-completion either. All in all these are more powerful than nano but less powerful than NP++ (which I'm not familiar with) and a fortiori vim or emacs.
Anyway, a stock vim, even built with "huge" feature-set won't check the syntax of your PHP files as you type or on save, you'll need a bunch of plugins for that.
I don't know about emacs, but vim can be used in "easy" mode like this: vim -y yourfile.php.
Vim is one of the two best editors out there, learning its basics is not that hard. You probably don't have much time to spend on it right now but, once you do, try it. It rocks.
Can you tell us a bit more about your workflow (server layout, use of a VCS…)? At a glance it looks like you are editing files directly on a production server which is not really recommended.
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About Vim and all the others being just editors.
Yes they all have the same set of basic features: ability to input text, cut, paste, move the cursor… but even these basic features can be implemented in many manners. You say that you want NP++ features in a CLI editor, we can assume that you have tried other editors and ultimately decided to go with it because it worked better for you than the others.
All the CLI editors are different, like their GUI counterparts they shine in one place and lack in another. Because you are a programmer you "need" some advanced features and any editor not having a full fledged search/replace system supporting regex, some sort of auto-completion, macros, ability to build and show errors and so on.
Vim and Emacs both offer these fatures and sooo much more either natively or via plugins. As far as I know they are the only CLI editors really suited for programming so, to be able to work directly on your VPS, and be productive, you don't really have much choice: it's either one or the other.
The first problems you may be facing is the abruptness of the learning path and the weirdness of their "models" but most vim/emacs users will tell you that once its internalized it's hard to come back.
Why Vim (or emacs)?
I don't have a specific selling pitch to serve you. I was an advanced TextMate user, for me it was the best editor and it fitted all my needs but I was a little bored.
Then I stumbled on a Python screencast where everything looked magical to me and I found other screencasts by Dereck Wyatt and others and I was hooked: the way they moved through their code, the way they search/replaced, the omni-completion, the crazy plugins (surround rocks), the freaking motions and text-objects…
I took advantage of a slow week to learn the basics and make/revert a lot of mistakes and now I look at TextMate the same way you'd look at Notepad (not ++).
Here are a bunch of additional vim links for you:
Ho, I just remembered another CLI editor: diakonos.
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