King's Gambit 3...d6 and question about KG in general

So I'm looking into this opening, and I'm doing some prep (using a database and stockfish), and I'm happy that as black I can keep a noticeable advantage in any line.

But then I get hit with a big surprise on move 9 while practicing online

8...f3 is a good alternative, but it also doesn't lead to much.

So my question is, can white equalize in every variation of the KG (including 3...g5)? And even if not there are so many sharp and messy positions you have to be prepared for.

I'm seriously considering switching to 2...d5 (which I've played before) or 2...Bc5 (which also seems like an easy to way handle the KG).

It happens only at low depth. Starting from d=20, SF9+ suggests 9. e5! as the top move. 

I'm definitely no pro. I don't use an engine much for openings. I basically just follow database games (if the players are GM strength) and then let SF think a few seconds on each move to check for any big errors, and that's how I'll make a repertoire.

So e5 really surprised me.

Well, I'm also amateurish.  Nevertheless, I like to use SF9+ at d=20+ to prepare my opening repertoire up to 10th move.  I guess that your method (GM databases + blunder proofing) is good too. 

On my machine, SF8, it breifly likes e5 at depth 20, but then it disappears out of the top 3 until depth 28.

When I have it show only 1 line, it doesn't like e5 until depth 29.

Oh I didn't know SF9 was out.

I got it just now. Seems to be the same. It briefly likes e5, but then switches to Qd3 until depth 28.

Ah, maybe the difference is here cuz I launched it with 5 best lines.  At depth 23/23, it shows 9. e5 (ev=-0.3) then 9. Qd2 (ev=-0.5). It could change at higher depths but 9. e5 is definitely one of top moves.

Oh, 5 lines. I usually just do 3.

As for the game, there's definitely chances for both sides because this would be a huge mess OTB, but surviving white's initiative isn't really what I want. So I'm thinking of switching to 8...f3, but also, like I said, just switching to 2...d5 or 2...Bc5

I know some 3...g5 lines give black a really big advantage, like over a pawn... but white will play into them because again, black has to survive an attack to prove it. So maybe I should just be content with a simple line that gives equality.

Well, I'm not a fan of KG. Personally, as white, I prefer to play 2. Nc3 and the Vienna gambit 3. f4 in the case of 2...Nf6). It's not messy and gives to white clear winning chances if it's accepted. 

As black, I don't know what I'd prefer, it happened rarely in my games. 

I see the vienna rarely OTB, but I get good positions against it after the main move 3...d5.

I'm honestly not sure why white players like it

Please try to refute this 2. h3. 

Right.  It's not refutable (at the currrent state of art) so it's relatively good (though suboptimal). 

Almost no openings can be refuted except for maybe 1. f3. A Rapport game at the Reyjavik Open went 1. a3 h6! And by saying this, I am in no way supporting Yigor. 

Pretty sure openings like the Latvian are forced losses.

Maybe moves like 1.g4 and 1.b4 as well, at least in something like ICCF play.

OTB it's not a loss, but in ICCF I heard a guy say (on the forums a long time ago) that it's a loss.

Well here is an opening that is not refuted

Also about the KG question, I am not sure I would almost always want white in the KG though as there is more attacking potential. 

I guess you don't play the KG as white, so it's useless to ask, but which black defense would you not like to see?

I guess 2...d5 or 2...Bc5 which don't let white get an initiative / attack like many other lines do.

As long as we're posting random games, check out this game I found by accident.

After 9...Be6 the engine shows close to 0.00, but many various lines I tried for black all lead to a white advantage. The problem for black is White is really flexible here, and has different good ideas.

Too bad there's no way to reliably get this position as white