There are some simple steps they could take.
1. Don't keep announcing new routes if you have continually had problems securing aircraft on time. Have a decent buffer of time between aircraft due to arrive and operate (of course this costs money but its better than continually destroying your brand) and if the plane doesn't come or seems highly unlikely with two weeks to go then postpone (at least cancelling more than 2 weeks in advance you won't have to pay compensation to all the passengers who did book)
2. Lease in support to cover for delayed aircraft (surely the leasing contract should have some kind of clause to cover such needs if it is as we are told and all the lessors fault - and if it is delayed aircraft why completely scrap the route rather than just postpone.
In terms of 1 above, there does seem to be an attempt to build in some buffer time, for example it was said that FLBB is due this week, but is not needed to operate the schedule straight away. So they might have needed to delay the IOM start by a few days (if this a/c was earmarked for that), but not bin it completely. Maybe some truth in that a commercial decision was taken (due lack of bookings), albeit very/too late in the day.
In terms of 2, again perhaps a commercial decision based on lack of bookings (where it would make no sense to go to the expense of a lease-in - depending on how much of that a lessor may or may not cover)
I'd like to see Flybe 2 succeed, but in some respects at least they're not helping themselves by making a better job of managing the headwinds they currently face.