I hate this car. The gears are my biggest pet peeve. They are constantly sticking and I have had then checked a number of times, but apparently that's just the way the are. Never again will I get a Fiesta. I'm getting rid of mine.
Your problems = you are driving a 13 year old pos commuter.
I assume this is the normal automatic rather than the CTX variant - if this is the case you may need to drain and refill the automatic gearbox fluid as this degrades over time. Unfortunately the marriage of an old pushrod engine and a heavy slushbox is as likely to be unhappy as most UK marriages (although the car might last longer).
Like the last commenter I think you are expecting too much of a cheap car which is three years past the end of its design life. If you want to get under it, you will probably find it is happily rotting everywhere too.