Only if its plural, like conclusions.
"In conclusion"
In your case, the question is, can a sentence come to a conclusion. Try again.
No
NO
you can start a senetence with or but it wont be proper grammer.
Yes.
Yes, sure.
You did a proper job of it.
It's perfectly fine to start a sentence with likewise, just make sure you have a comma after it.
Yes, "Hiking" should start with a capital letter in a sentence because it is a proper noun.
a conclusion sentence is a sentence that concludes either a letter, peice or a story.
No, a sentence can begin with any kind of word. The first letter of a sentence is always capitalized to mark the start of the individual sentence, not because the word is a proper noun.