Modern Hebrew is basically like Esperanto. It's an artificial language, restored by Eliezer Ben-Yehuda אֱלִיעֶזֶר בֶּן־יְהוּדָה.
I wouldn't call it that. What Ben-Yehuda did was prescribe a modernized form of the language with new vocabulary. His intention was to make Hebrew useable in daily life. I suppose by doing so he had to change its character, but fundamentally it is still the same language.
Many words were completely invented by him, or he took existing words, like lightning for electricity. חַשְׁמַל khashmal (חשמל)
Well, it's better to say he adapted them rather than invented them outright. חשמל is a good example, although it actually means something like "coronal discharge" (it's hard to translate). The word for lightning is ברק (bārāq).
He also made the grammar simpler and ditched the vowel signs. He designed it to be simpler than Ancient Hebrew.
He did indeed simplify the grammar but you can't say really he ditched the vowel signs because they weren't part of the orthography to begin with. The original spelling for Hebrew didn't write vowels. The vowel points were developed in the Middle Ages and are used only when precise reading is required, like in religious texts.