Everyone here's said most of it, but you really just can't ignore the major sources and expect us to continue to take you seriously. Shadowcraft is a surprisingly and impressively accurate DPS tool for assessing capacity and changes in gear, as well as optimizing reforges and gear
SimulationCraft is not the website that shows max DPS specs, at all. Everyone knows that because they loaded the "best in slot" profiles into SimC and came up with those values. The simulationcraft program itself allows you to simulate any character you want under varied conditions, times, buffs, debuffs, and ability usage (if you work at it). It also provides (both on the well known page and in the simulator) a lot of serious breakdowns of ability usage by time, damage by ability, energy regeneration by ability etc.
If you're so embittered by EJ, don't come here asking us to give you the values they provide... go gnab them out of SimC yourself. It's a powerful tool if you learn to use it. Short of that, Shadowcraft is really user-friendly. It'll answer your gearing questions.
The ideal for pre-envenom is to be around 80 energy, so you can immediately pop 2 mutilates and (if needed) burn a rupture without losing a beat or losing the envenom buff uptime. "Clipping" the buff is when you envenom with the buff still up, and if you needed to refresh rupture or don't have plenty of energy, it's a DPS loss because you can't immediately Mut again.
You're honestly nearly asking for an entire assassination guide in the general direction of your queries, which EJ provides. Hate EJ? Try Noxxic or another site, but don't ask us to rewrite the guide for you.