Still Fredo made a deal with Ola and Roth to get Mike to ease up on the "negotiations" for the "big deal" in exchange for something on his own. Maybe Fredo was playing both sides.
Well, I just don't see Fredo in any position (status or knowledge) to try and get Michael to ease up on the negotiations. Thus, you are probably right that Fredo did exaggerate his family position when he talked to Ola.
Ok, Oli, so lets take it to the next level just for yucks. Hyman Roth went back for decades with Vito Corleone. He knew all about Sonny, probably about his temper, and surely about his death. Through Moe Green he had to know that when things were going badly for the Corleones in NY, and while Vito was recuperating, that Fredo was sent to Vegas with the cover story of nerves, but in truth to keep him out of the way. He also probably heard from Moe about what an idiot Fredo was, his cocktail waitress exploits and so forth. He also had to know that Vito made a deal and brought Michael back, passed Fredo over, and that eventually Michael became the Don. He also knoew exactly "who gave the order" to put a bullet in Moe's eye.
Moe was no idiot, and I don't believe for one second that he really believed that Fredo could influence a business decision Michael was making. Besides, the "big deal" they were working on was Havana. The details of the negotiatiions had to be who was getting what share of which venue, how much money had to be paid and so forth. As we know further, Roth was always running around proclaiming Michael to be his heir apparent when he died of that 40 year old heart attack.
SO...........when Ola happened to bump into Fredo in Beverly Hills (wink, nod) la allowed Fredo to exaggerate his position in the family and made the ensuing promises about him getting something for himself. Now since Roth, and by extension Ola knew Fredo could do nothing to get him to change Mike's position on negotiations, they wanted him for one thing only...to set Michael up for the hit, and to use Fredo in some way to make it easy for them to be successful. So the drapes do get opened, and something goes on, according to Deanna, right underneath her window.
So at this point we can say the drapes were opened by Fredo... maybe he told a maid Mike wanted them open.. who knows...and we know Fredo had something to do with the hittters who were on the property.
We can also easily surmise if Roth had been successful in killing Mike, that Fredo would be next on his list. I would suspect a meeting in Havana, where Fredo would be safe, might have been the ticket.
