I think the first thing is always to protect yourself, legally, financially, and emotionally. That is non-negotiable. You need to prepare yourself for the legal issues related to the divorce, to custody issue, to money issues. You also need to keep working on detachment so that you don't keep giving her the power to affect you emotionally. That's why getting out of the house, GALing, and working on yourself are so important.
After all of that, if you can still manage to be nice, pleasant, cheerful, strong and assertive -great. But I think you are putting the cart before the horse if you focus on those things first. Being pleasant is always a good idea with anyone, but not if it means you are exposing yourself emotionally or letting her roll over you financially. This process is more about saving yourself than saving your marriage. If you are able to save yourself and find the balanced, strong, assertive person inside of you then perhaps there is a chance that the W will see that and come back. But you can't control what she does, and at a certain point it might not even matter to you what she wants to do.
So, by all means, be the lighthouse, pave the way back, but protect yourself and shift your focus onto yourself. You deserve a lot more than the sh#t sandwich your W is currently serving you.
W 34 Me 42 Married 7 years together 8 0 kids 1 beloved dog BD 4/6/2018 I moved out 4/7/2018 I moved back in alone 8/05/2018 I file 3/06/2019 D official 5/7/2019