Do these sentences carry the same meaning?

[Mr_jim]

Do these sentences (given in pair)carry the same meaning?

One thing, please also tell me, which one of the two below, will the Native English Speakers prefer to use in Everyday Use.

Here we go...
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1> I guess, I have done it before.
2> I might have done it before.

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1> I bet, I have told you the story.
2> I must have told you the sotry.

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1> I feel, you need to do that before.
2> You should have done it before.

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[Rusty]

1> I guess, I have done it before.
2> I might have done it before.
(Both OK and natural. 1. means "I expect/think I have done it. 2. means Maybe, but I'm not sure I did it).
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1> I bet I have told you the story.
2> I must have told you the sotry.
(Both common. No comma necessary in 1.)
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1> I feel you need to do that before.
("Before" puts the action of the sentence in the past tense.
I feel you needed to have done that before. This is more awkward than 2.)
2> You should have done it before. (this is natural and common).