It is all normal dog behaviour but it is not all essential dog behaviour and it is not all behaviour you, therefore, have to live with.
The magic of dogs is the sheer range of behaviours they can be trained/habituated to. In all 3 examples, the dog is doing what it is doing because he is being rewarded for it. If he no longer got the reward he would give up the behaviour. If he got rewarded for an incompatible behaviour, he'd give it up even quicker.
Lead pulling...
Current reward: getting to move forward to a new location and smells. Maybe some touch-triggered reward from the feel of the pull, particularly if this has become linked in his mind to the thrill of a walk.
This IS a hard one for springers and cockers, many of which have elements of pulling bred into them. Often sniffer dogs are trained to 'pull' their handlers along to whatever it is that smells right.
They are also bred to quarter - which means dart back and forth sideays as they move forwards. This is not very compatible with loose lead walking.
However, as PP said: they are exceptionally good at learning I can pull with X walking me but not with Y. So you can train this when you walk the dog and let your DH do whatever he wants. It's easier if you both do exactly the same, but it can also be done by just one walker. Dogs Trust method is as good as any.
New reward: only gets to move forward when by your side, maybe coupled with training treats.
Stealing cake...
Current reward: cake!
Yeah - lots of dogs steal things from the side and it's one of those things that, once they've stolen one thing (a nice mouthful of cake) it is a behaviour that has been so rewarded it is always worth it to them to try again.
Don't leave anything in dog reach - the better you are at this, the less chance there is of the dog managing to get anything, the sooner they give up trying.
Eventually age stops them too - jumping up for side-food tends to be a young dogs's game.
New reward: none - it's often more effort than it's worth to try and reward him for not counter surfing. It's easier just to keep ood out of reach until he gives up.
Plate surfing...
Current reward: a lick of your shepherd's pie gravy (or whatever).
Again, it is entirely possible for the dog to learn they never get anything from you or your plate and so leave you alone. Even if he still pesters and succeeds with your DH.
As pp has said, a nice way to do this is to ensure the dog only ever gets any food when lying down away from you. You can do this with a kong, or by popping a mat down (as a target) and keepingg a few training treats with you when you eat - every few seconds toss one onto the mat.
If the dog only ever gets food from the mat and never manages to steal from your plate, they will wait on the mat. Over time the frequency of treat tosses can be dropped.
New reward: food treats only given on a mat, away from you.
Or get a baby gate and shut him out the room during dinner time 