[Nokia X] Jack Phoenix:
You're not totally out of luck, but...well, it's complicated.

You can install MoreLocale 2, a free and open source app which requires no rooting to force apps which have a Hebrew translation to use those. Essentially it's similar to the Language Enabler app which you've tried and which really didn't do the trick for you. Know why? Because the Nokia X's default ROM ships with only a handful of languages, which are:

Bahasa Indonesia (Malay)

Bahasa Melayu (Indonesian)

Čeština (Czech)

Deustch (German)

English

Español (Spanish)

Français (French)

Italiano (Italian)

Magyar (Hungarian)

Polski (Polish)

Português (Portuguese)

Română (Romanian)

Slovenčina (Slovak)

Tagalog

Tiếng Việt (Vietnamese)

Türkçe (Turkish)

Ελληνικά (Greek)

Беларуская (Belarusian)

Български (Bulgarian)

Қазақша (Kazahk)

Русский (Russian)

Українська (Ukrainian)

العربية (Arabic)

हिन्दी (Hindi)

ไทย (Thai)

中文 (Chinese)

Any and all other languages not listed above are not natively supported by the default ROM, but you can manually add the support...or more precisely, try to, since you have a rooted device. You'll need to install Xposed Framework and the resOverloader module for it. You'll also need a computer with:

The official USB drivers for the Nokia X

Android Software Development Kit (SDK) installed

Java Software Development Kit (SDK) installed

apktool

Using these tools you are able to extract the system apps' files and the necessary framework .apk file from your device into your computer. After you've decompiled each and every app, you'll need to create a temporary folder for your resOverloader work; I created mine in D:\ so the full path to the folder was D:\resOverloader\. Then you'll need to create a folder inside the resOverload folder and name it according to the app's package; say, if you wanted to translate the HERE Maps app, the package -- and thus the folder -- would be called com.here.app.maps, so the full path would be D:\resOverloader\com.here.app.maps and you'd need to copy the original strings.xml file here from the sources decompiled by apktool, and then manually translate it! Talk about a tedious process -- took me over a week to translate most of the system apps and whatnot.

Once you've translated whatever you want and need, push the resOverloader folder to your device via the "adb push" command into /storage/sdcard0/ (which would mean that the path to the HERE Maps app's translations would be /storage/sdcard0/resOverloader/com.here.app.maps/). Reboot, or if you want to avoid rebooting, go to Settings > Apps > Manage apps > choose the "All" apps view > find the respective app (say, Maps), tap on it > choose "Clear cache" and you may also need to choose "Clear data" (doing so deletes your data, so be careful and don't use this option if your device has valuable information which isn't backed up anywhere!)

...

By the time you've done all this, you'll notice that despite all your great and time-consuming efforts, some pesky apps won't display in the non-English language you've chosen, no matter what. The biggest offender is the Settings app (com.android.settings), but the Phone app also has some dialogs and whatnot in English, despite that I've translated them; Messaging and Contacts will require the caches to be purged in order to work correctly. Internet (built-in Xpress Browser app) and Camera display menus which contain multiple choices (such as Camera's "Storage" option) display the menu label in your chosen language, but the actual options in English -- this is likely a problem with my translation files, though, as opposed to the resOverloader module or the actual device firmware, I'd guess.

So what do you have at the end of the day, if you've followed my above "guide" patiently and correctly? A Nokia X device which sometimes speaks the desired language to you, and often also speaks English, whether you want it to or not. How to fix this, then? I have no idea, I'm afraid; if you know someone who does or you know yourself how to fix this, do speak up, please! It would be lovely to have the X support at least all the languages the Android Open Source Project (AOSP) does. And yes, I'm somewhat annoyed by the fact I spent over a week translating and fine-tuning these strings.xml files only to find out that they don't quite work "as advertised"...

As for enhancing the Nokia Keyboard to support a new language or multiple languages, I don't know anything about that either -- though it's something I'd also need to do for my native language, Finnish, which isn't supported by Nokia X natively -- but maybe someone else in this forum does?