Why not.
From Venice to Paris is a long way to walk, so I took the train.
no
Always start the beginning of a sentence with a capital letter.
Yes. 'Thus' is another word for 'therefore'. Thus the sentence you start of with 'thus' should be an explanatory sentence.
No, you should not. You should only capitalize a word when it is at the start of a sentence or when it is a proper noun.
No, why should it be? Well if it's at the start of a sentence, but really, how many sentences start with the word example?
However. On the other hand.
Only if it's the first word in a sentence.
Since 'felon' is a common noun, it is only capitalized if it is at the start of a sentence.
No, "diabetes" is not capitalized unless it is the first word in a sentence or part of a proper noun.
You start a sentence with whatever word you need to start it with. A sentence can start with "A" if it needs to. A sentence just needs to make sense.
can you start a sentence using the word phishing?
And is a coordinating conjunction; therefore it should never begin a sentence. Ironically, though, the preceding sentence is correct because and is used as a word, not as a conjunction.