Sure, you can keep all of those Enchants up, but it's not like yuo'll get any benefit out of it. With 14-16 in Energy Storage you'll only be able to put about 9 in Prot and Healing.
There aren't many good sustained enchantments. Sure, you can divert half of all of your allies' damage and take a bit yourself. You can increase their health by 150. You can give them *WOOHO* 5+ damage. You can give them 3+ energy regen. You can make enemies take a whopping 2 damage! Or you COULD Prot Bond them but lose 4 energy every time any of them take a hit (Fire Storm would bring your energy to 0

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The only way that this would be any good at all is if you used Symbosis and you can only have one of those up at a time on each side and if it dies and your spiriter doesn't have Oath Shot, your build is completely useless.
An interrupt ranger or mesmer - unless the Ether Renewal user has found some way to spam Glyph of Concentration extremely fast - makes that elementalist ineffective, or if they can interrupt Ether Renewal, useless and out of energy.
A good Mesmer can keep any Ether Renewal user grounded. This skill is not imbalanced; it may be very powerful, but not imbalanced or exploitatious.
What about in PvE? Yes, this skill helps alot with UW soloing but we, at times, forget that there are still Mo/W UW soloers out there. I've even heard of a few E/mos using Mist Form instead of Ether Renewal to solo UW.
So, I would say that alot of the hype is just that: hype.