Scandinavian declined 2.e5

If your opponent wants to push d4, you can't stop him, and then you've got that French pawn chain pretty much no matter what.  You don't need to be saddled with typical French issues, however.  The two most common ways of meeting it are 2...c5 with a quick liquidation of the d-pawns and an easy game for black (at least early on), or 2...Bf5, when you've pre-solved the French "bad bishop" problem.  It becomes a Caro where you were able to get a leg up on your opponent by playing ...c5 in one go.

2...c5, 3.f4 is an independent try, but then you're not in a French structure to begin with, so it doesn't meet your conditions for worry.

I suppose there's nothing preventing you from playing 2...Bf5, 3...e6, and 4...c6, transposing into an advance Caro, but that seems curious when you had many objectively better ways to proceed.

I play 2...c5 since I know it's best and when my opponents play 3.d4, i reply with 3...e6 because i dont really know if it's good to play 3...exd4.

I play 2...c5 since I know it's best and when my opponents play 3.d4, i reply with 3...e6 because i dont really know if it's good to play 3...exd4.

I play 2...c5 since I know it's best and when my opponents play 3.d4, i reply with 3...e6 because i dont really know if it's good to play 3...exd4.

I play 2...c5 since I know it's best and when my opponents play 3.d4, i reply with 3...e6 because i dont really know if it's good to play 3...exd4.

I assume you mean 3...cxd4.  Yes, it's good.  You're trading a flank pawn for a central one without giving anything up for the opportunity.  Rejoice and take.

Against 2.e5, do not transpose to the French.

In the French, Black blocks his bishop to get in c7-c5 in one go.

In the Caro-Kann, black takes two moves with the c-pawn to get the Bishop outside the pawn chain.

After the bone head move 2.e5 against the Scandinavian  (2.exd5 advantage White), black gets the best of both worlds.  Bf5 AND c5 in one go.  Black is a tempo up in the caro-kann.

exactly, would always want to be black here because white has obviously no clue what they are doing

I don't see why you would want to transpose to the French. Here, you can get a kind of French defense where the French bishop actually gets out.

You see, in the French defense, you need to play c5 and break out. There's a term called the French bishop. It's the light-squared bishop, which is locked out of the pawn chain. You're sacrificing it's activity (for the duration of the opening and maybe the middlegame, I don't know, I haven't studied the French). If you choose to play the Caro-kann, you're instead sacrificing the pawn and two tempos.

This way, you can kind of get an extremely powerful French defense from this position. If you can get the bishop out, play c5 without wasting a tempo, and not sacrifice the c-pawn, you can get a more comfortable position than a regular French or Caro-kann.

The undeveloped bishop on c8 just means "unmoved". It's actually doing a pretty nice job along the c8-a3 diagonal. If you were to move it, it would immediately get kicked, and is already controlling enough squares to be considered "active". Sure, you can go to b4 to target the knight if it goes to c3 if you like.

If you've studied the Ruy Lopez, it's like white's dark-squared bishop.

Yes, I know this probably isn't the right move order, but I'll put it anyways. The dark-squared bishop controls enough squares to be considered active. The bishop can be moved to g5 to target the knight, just like here you can move it to b4.

Of course, depends on your preference

The good thing about the Scandinavian for black is that it is one of the most forcing openings: white pretty much has to take the pawn. And why not? White is just better after 2.exd5. If you do play 2.e5, the best thing to do after you lose the game is claim it was a mouse slip, and you meant to play exd5.

the dark squared bishop often waits on the c1-h6 diagonal untill it has a purpose (often to sacrifice

ive had positons like this in the ruy where taking on h6 could be valid