Whats the break in ritual for the opti max, and is it really necessary to do it ?

You should have gotten an Outboard Operation, Maintenance & Warranty MANUAL with the purchase of your Mercury Motor. If you did, check out page 50-51 for the break-in procedure and YES it is necessary or your warranty will be VOIDED if you have problems because you didn't break it in properly. I am copying from the manual ver batum:

1. You do NOT have to add extra oil to the gas as was the old procedure. It should be set to automatically add extra oil from the reservoir. Make sure the oil reservoir is at the full mark with the engine tilted straight up and down. This extra oil mode lasts for about 10-hours of operation then it goes back to normal mix.
2. The first hour of operation, allow the engine to warm up for 30-60 seconds. Then run the engine at varied throttle settings, the majority of the time between 3000 and 4500 RPM (3/4 throttle). Change engine speed approximately every 2 minutes and AVOID continuos operation at idle speed for more than 10 minutes. Short bursts of full throttle for periods up to 10-seconds are acceptable. Avoid trimming the outboard up beyond a vertical trim position (straight up and down) during this operation.
3. For the next 3 hours of operation, change engine speed every 10-minutes.

That's all there is to it.

Remember, the shop can set up a computer diagnostics test on your engine to read how many minutes you ran at what RPM - it will tell on you if you do not follow the proper break-in procedure.