Completely depends on what you're doing. Assuming magicka based because of tank/heal.

Solo: all, or almost all, points into magicka

Dungeon tank: For max level, you'd want to hit 28k+ health, rest either all in magicka or split between magicka/stamina if you have to block tank. You can do all vet dungeons besides white gold/prison with less health but I'd still aim for 28-32k

Trials: all health/stamina

PVP: completely depends what you're trying to do in PVP, heal/damage would be health/magicka, block tank would be health/stam

For armor, can kind of base it off of what I mentioned above. If you're going magicka heavy then seducers set, if you need to be tankier than hist bark or armor master.

Depends how much you want to respec attributes. You can do all content except for IC vet dungeons, trials and vDSA by having a balanced health/magicka build, 5 heavy, 1 med, 1 light (for undaunted bonus) with 1h/s, resto staff and maybe a different set of jewelry for whether you're healing or tanking.

A lot of the champion points for being a heal tank are also the same points needed as a healer, so I never have to respec my CP.

You can be a better healer if you carry an extra set of gear, and swap from 5pc heavy to 5pc light, change your jewelry out and respec your attributes to all into magicka (since your imperial, shouldn't need any or very few into health).

If you want to tank IC vet dungeons, trials or vDSA then you'll be block tanking more so just dump enough points to get to about 17k+ stamina and change your loadout to be 1h/s for both bars.