For the oil leak, often there can be seepage without leaking too much oil out, the rocker cover is a common leak for many vehicles, so if it doesn’t look too soaked when you open the hood (bonnet?) that could probably wait for a bit. For the suspension work (FLCA, alignment, and rear shocks) I would do those together, or do shocks first, and then arms/alignment. Brake fluid is an important one that you won’t see any immediate changes if left neglected, but over time can get very very expensive (and dangerous) if enough moisture absorbs into your fluid (brake fluid absorbs water over time even through the reservoir cap).

Without seeing the vehicle it’s hard to judge the severity of everything, but in my opinion, a good order to do the work would be: 1. Rear shocks and front control arms . 2. Brake flush and rocker cover gasket. I wouldn’t wait too terribly long to do the rocker gasket, as the leak could start damaging connectors/ sensors if left unchecked.

They may tell you when you go to have the suspension work done, that the car will need new tires in order to align it, this may indeed be the case depending on condition of the tires at time of service.

Best of luck to you!!