You dont need to be nervous. In a good trial group, you should have two healers taking care of you. Your stats actually look more than good. In most trials 40k health is enough. 20k stamina and 15k magicka are also fine. Actually for most tanks those two stats arent that important. Only importing thing is to have more stamina than magicka, so spear shards and orbs restore stamina. Another important point is the trait of you gear and what jewelry glyphs you are using. I recommend a lot of robuste armor traits to decrease your blockcost. For the jewelry enchantements shieldplay, reduced stamina costs and magicka recovery are the best enchantents.

If you are built around that you can permablock against one boss, you will do fine. Normal trials arent that hard for the tank, damage isnt that high and enough healing should be provided. Just provide debuffs with puncture and heroic slash, also engulfing flames is nice. Otherwise shield up a bit and permablock and there shouldnt be any problem. Also the group will love you for applying debuffs and regular warhorns ultimate. I dont think there will be much problems, when you are experienced with the harder vet dungeobs.

surely he could, but he wouldnt see any any benefits from doing so. he only would see a decrease in his shield size. but max stats beside health arent important for tanks, since you usually dont hit full stats during fights of minutes. maybe if he would be an argonian with tristat pods you would hit maxumim resources by drinking a potion, but in every other case you dont have much benefits by pushing max magicka and stamina.