Well generally if someone is passive against Ermac, it is because they are not familiar with the match up. OR they can be expecting pokes in certain scenarios and are looking to bait them / block them and start their own pressure. In which you are taking advantage of this.
If you do not mine me asking, what exactly have you been doing to rush down the opponent ?
Hasn't happened to me yet, but why am I not surprised ?
If i was back in the US it would be so much easier to show some of my gameplay, unfortunally im not at the moment so ill try to explain my offense as best i can ( or if anyone here is in EU atm i could play them, let me know it would be fun to play some of you guys) well then, lets see, i was a NightWing player so im very poky poky bait if you know what i mean, this is my oppening set up to see how the opponent behaves and if he will block my more advanced stuff:
i do 11 a lot to test the waters and to go into my other set ups, most comun for me, if the opponent is not that strong, is to mix up either instant Air Force blast or B3 after the 11 is blocked. depending on what i see ill adapt, if he defaults to low block a lot ill do instant AFB into F4 and combo... a well done AFB on hit staggers well enouth and leaves the opponent going WTF just happened!! long enouth for a F4 to connect on the tip... if he starts catch on to this, i mix all 3 options up. AFB into B3 mixup, 11 into B321.
I love doing F2 for some nice frames and going for something tricky like D3xxAFB into the mix ups i mentioned, or F3 mix ups...
I use B124 a lot as my spacing tool, since iv been playing Ermac for a long time i mostly figured out the jump arcs for everyone in the roster, so i became quite good at anti airing with B1 and going for a combo from there, but i do do the usual B12 mix up or just let B124 rip ocasionally.
As for far away game, i rarely do standing fireball, i just see litle profit from it, so i always try my best to do it insta air as well, can catch them running or jumping, so its a win win scenario for me, i actually like using levitate a lot for 2 things, ground slam obviously, on some MUs its quite nice to be honest, and i like to Bait runners with it, by doing Levitate cancels or Vanish, they are not the best of tools but surprisingly enouth some ppl still get caught by them... Also ppl like the 222 string a lot, i usually dont use it unless my opponent is very good, and i would need another layer of pokes to mix then up...
You might have noticed that i like to do insta air stuff a lot XD, well its fun to do and online ppl never expect a random dude to have that much execution to do that kind of stuff so i really really like doing it, and it works really well since its another added layer of mix ups that ppl never look for...