I guess you know allready about the barotrauma stuff since you've had it for so long. Let me put it to you this way. You might get through a class one if your fit for fight during the exam, but if youre future airline gets a sniff of that you will be grounded for a month or so with regular intervals, you might not get the job.
More to the point: You've allready felt the pains of bad sinuses (spelling/grammar? oh that goes for my whole post...) on ground. Have you ever had the chance to feel what it's like to have a sinus problem in the air?
To put it short, it's worse than torture. I've had it a couple of times and I'm now really careful to not get in that situation again as it's absolute agony. If the smelly brown stuff hits the fan, it'll make you incapacitated and possibly to the point where you'll faint and thus be completely useless up front.
As I've understood things, what happens is, in the descent or as the pressure increases outside of the blockage, you build up a suction in the sinuses. This will, if sufficient blockage/diff. pressure is present, pop the mucus membrane that lines your sinuses out of its position. When this happens, you're grounded for indefinate time as this will most likely get infected. As you I guess you know, sinus problems usually linger around for quite som time and may very well ruin your career as it has for many other pilots.
I hope I didn't scare you too much but sinus problems and aviation don't mix well.
/LnS