Newbie upgrading question

Is it a good idea to upgrade all the walls to the highest level before upgrading TH once everything else is maxed out? I am currently at TH Level 4 and all my buildings, camps, resources (collectors and storage) are maxed out. All the defenses are maxed out as well with the exception of the walls, which all 75 are currently at level 3 and working on level 4. But I was wondering if it's a good idea to keep upgrading the walls and then upgrade TH? And lastly, once I get to TH level 5, any thoughts on priorities for upgrades/new building projects?

Yes, do them

Definitely upgrade your walls before you move up Townhal, first priority when you do move up buy all the defences and resources items that are in the store then upgrade them to the level most of your other ones are on and then moving on to upgrading the mortar

on the low TH levels, walls should be rather cheap. How many raids do you calculate it takes you to max your walls ?

regarding on what to upgrade first after the TH upgrade, there are different philosophies.
Personally, I would suggest to first upgrade the offense:
army camps, laboratory, spell factory, clan castle and all the troop upgrades of the troops that you use frequently.

a better army helps you get better loot in your raids...