Hmm, I do good against some Olimar players, and bad against others. If Shield Grabbing is really popular than try to approach from behind. Retreating Fairs won't work, so do a delayed (activating each part slowly Dancing Blade with the down ending might shield poke him). He's good, but weaker than Marth in the air, so if you get a chance toss him. Olimars are heavy on the shield, and very light, so if manage to mindgame him by chipping at his shield lots of futile Fairs, and then land a solid shield breaker when he anticipates a Fair can break it if you're patient. On the light Olimar, that may as well be a stock when followed up by the Fsmash tipper fully charged. Also, you can usually run through Pikman toss, just watch where the Purples fall into the line up. Don't occupy yourself with getting them off, you need that time to be offensive.
If he starts spamming Pikman, and you need time to think, just hold your ground and bat them away with a jab. Though, it's like I said before, running through the stream, avoiding getting knocked back by a purple, and poking through the shield with a slow down Dancing Blade works well. Remember, to shield poke with Dancing Blade, IT MUST be slow. Dancing Blade doesn't Shield Poke all by itself, but if you delay it, the shield's natural depreciation will help the shield poke, and this will lead to the last hit of Dancing Blade hitting your opponent (works on all characters, not just Olimar). This won't work if your opponent perfect shields the beginning, or dodges some of it, but I manage to get it off fairly often.
I'm currently experimenting with RARing but using Fair with Marth, to allow Marth to land behind his opponent, but facing them, while using Fair. While this doesn't cause tip, it might provide excellent placement and work very well providing mind games.
Also, little tricks like air stalling with the first slice of Dancing Blade while pinging the opponent's shield, then punishing the attempted grab with the first slice of the Nair, and then chaining that to Dtilt, etc, also might help a little.
If I think of anything else, I'll let you know. I've fought some of the best Olimars on the East Coast (won some lost some) and I don't find them impossible to beat. You can't be defensive in the conventional way, but you can't be over aggressive or impatient.
. The problem with dancing blade however, if I do it slow theres more opportunity to get punished from shield, (broken grab range). I'll definetly try it however and all these other tricks next time I play a campy olimar. So far, my main strategy is to work the whole match into gimping them by fair spamming off the stage. The main problem is I just cant think when I get mad / frusturated...
