After 1d4 d5 2e4, I would play ...ed and if 3Nc3 Nf6 4f3 c6 now if 5fe e5! is I think good for black. He has nice open lines for his development. While 5 Bc5 Bf5 (or 5 ...b4!? perhaps) 6g4 Bg6 7g5 b4 8gf6 bc4 9fe4 ef6 doesn't seem to give black too many problems.

1e4 c6 2d4 d5 3Nc3 de4 4Bc4 transposes into the above after Nf6 5f3

Thank you for your reply. Yes, you’re right, 4..e3 cuts down on my homework because it applies to both lines (1d4 d5 2e4 and 1e4 c6, etc).
I had thought about 4..e3 (and I may try it), but look at 1e4 c6 2 d4 d5 3Nc3 de4 4 Bc4 Nf6 5 f3 e3 6Bxe3. I think White is happy here –lead in development and undoubtedly it won’t be new to him.
My judgment (about the BDG) is perhaps clouded because I’ve only recently taken up the C-K, and I’ve already lost 0-2 to the Bc4/5f3 line.
[I don’t yet have experience of the Advance Variation with Bf5 –I’m trying 3..c5. Because I fear that White knows more than I do I’m avoiding mainline theory, until my experience builds up.]
When I play 4..Nf6 (or 4..Bf5) I can feel the power in that piece, not so after 4..e3.
I don’t mind White winning back his pawn (5f3 Bf5 6g4 Bg6 7g5 Nd5 8Nxe4) –he’s made some concession with Pg5 I feel, but spending a tempo to hand it back with 4..e3 ?
I am forgetting Rule Two of Fight Club (Never argue with the Master, especially not in public!)
Publishing.com is great, why didn’t I join sooner?

Perhaps I am asking too much of the opening? I want the pawn (or compensation for handing it back), and a solid position that isn’t going to be overrun, and I want White taken away from his regular lines. A tall order.
Nf6+Bf5+c6 looks sound to me, so I’ll try a couple of times more and if it doesn’t work…
It’ll have to 4..e3.

I am looking for a simple system to play against the BDG. To save my homework, I want something that I could play after both 1d4 d5 2e4 and 1e4 c6 2 d4 d5 3Nc3 de4 4Bc4.
I’m not looking for an outright refutation, just a fairly solid line that damps down White’s attacking potential.
I’ve had 1d4 d5 2e4 de4 3Nc3 Nf6 4f3 Bf5 5Bc4 c6 6g4 Bg6 7g5 Nd5 [idea Nd7+e5] and 1e4 c6 2d4 d5 3Nc3 de4 4Bc4 Nf6 5f3 Bf5 etc.
In a recent reply I felt that you might have been a bit dismissive of the BDG. It is quite dangerous at Club level. After constantly watching for tactics Black can become fatigued, and he has only to miss one cheapo and he’s got a lost game.
One problem is that White may be playing BDG all the time and be au fait with the  ???subtleties. I don’t want to have to learn several variations of a mainline only to find my opponent can produce a novelty with which he has had practice.
In a nutshell: can I cut down on my homework with a ‘one size fits all’?
Has 8…Nd7 & 9…e5 got anything going for it?