So much can go wrong just because ingredients have been weighed incorrectly. If you’re just a little bit out it can have a catastrophic effect on flavour and consistency, yet it’s one of the easiest things to get right. Just concentrate at the start because any errors will only be amplified going forward!
If a processor creates a better finished product than doing things by hand and saves you time and effort in the process, then ‘go for it’! There are enough parts of the process that will require manual skill, so you may as well save time where possible.
If you’ve an hour to do a job that should take 70 minutes, don’t attempt it. Do it another day when you have more time. Always try to allow 25% extra time to any bake, because you never know when something may need to be redone.
Brush the cake with a jam coating first, this seals the cake and acts as a base for icing to be added, meaning a constant top level that doesn’t have bits of cake or crumbs lurking within.