You does not need to buy extended dry dock. If you are in need of certain ship then just need to use quick repair bucket, and these bucket are free .
1) New players don't have Akashi.
2) You are at severe disadvantage if your repair capability is 1/2 of another players. Especially when it comes to shuffling ships and minor damage.
3) Buckets should be reserved for events, wasting that is the worst advice you can give to a new player
4) A good player can simultaneously overload 4x dry docks' capacity and take advantage of Akashi's 4 slots.
Also there is no need for getting new API link unless you want to do monthly challenge quest.
1) You get 75 ranking points for completing challenge quest, which is easy before Admiral level 40 and doable before Admiral level 80
2) Even if you aren't going for ranking, you should always be getting the medal. It takes 4x medals (4 month or event medals) to get a single remodeling blueprint. (To unlock some Kai Ni)