All good except for point 5.
The thread you link to was written in February.
You are starting in late summer so I would just leave the polythene down, because it can then kill many weeds by light deprivation.
No rush to compost/soak the ground, you will benefit from leaving the cover on until say late October, then do some prepping, but even so its barely time to kill couch etc so I would re-cover until say May.
Meanwhile, grow some plants (spring sowings) to have ready for planting in May.
Patience will serve you well, and enjoy the holiday.
