Scale mana use/regen with how full your mana is + more items that interact with mana consumption

Mana currently feels too debilitating for the power of magic weapons. I propose two main changes to alleviate this. The first is to scale mana regen up as your mana bar fills up, from 0.8x at 0% to 2x near 100%. This would be based on the % your mana bar is filled, not how long you've been regening. This would reduce downtime and incentivize maintaining higher mana to benefit from faster regen rates. The second proposal is to halve all current mana costs and add scaling with how much mana you have left. Let's say mana cost increases by +15% per 10% mana capacity missing for example. There's also potential for offhand items/jewelry/armor set bonuses that grant stat boosts or effects when keeping mana fuller or above a threshold like 50%, such as lifesteal or + magic barrier. This would also add more synergy with the existing magic skill Fully Charged. You could also go in the other direction, + magic barrier at low mana etc. Also, please add jewelry that reduces mana consumption!