As the others here have stated, it's not necessarily a bad way, as there are modern translations. Some terms and sentences are bound to be difficult but that's just the nature of the Bible. KJV would be old English and I'd advise against it, not bad but just a much older style of English. NKJV, NIV, and NLT would be good options if that's something you're interested in reading.

it would depend on the version. there are modern english versions but even those might be written in a more stiff or formal voice than casual conversation/writing

No, it would be fine. There are many translations in modern English.

I'd say that it depends on the version you choose to read.