There is no justification in retaining slashing and piercing. These are flat, 100% uptime buffs that penalise you for not bringing certain jobs. They do not influence gameplay decision-making. They force your team to always bring certain jobs, which restricts diversity. The reason why effects like INT down and Storm's Path were removed was based on the same reasoning. If you're going to force every party to bring either a WAR or a NIN, then you might as well force every party to bring either a DRK or a MNK. That was, and still is, bad design.

Slashing isn't the only reason you want to bring a WAR to a party, nor should it be (if it is, the job has serious problems). WAR has phenomenal enmity generation and burst. It has the highest mobility and the most flexible stance swaps. Even if you restricted WAR's strengths to these specific areas, it still would be a valuable pick on most tiers without actively restricting groups who want to run PLD/DRK.

Veil and Shake are not problems in themselves. Veil was present throughout Heavensward, and wasn't nearly as much of a gamechanger that Path and Reprisal were. You're comparing a two minute recast buff to nearly 100% uptime. If anything, I'd like to see Veil function more like how Shake presently does (barrier shield which doesn't require a heal to trigger and also applies to yourself), and I'd like to see Shake apply temporary HP instead, in line with WAR's other thematic abilities (how does a non-spellcaster create a magical barrier that absorbs damage?) But the limit-gauge generation associated with Veil and Shake needs to be removed. These abilities were intended as a defensive buff, not an offensive tool.

Anything that forces you to bring a specific job is intrinsically problematic. Raid dps buffs are one example of this. 100% uptime buffs are another. No tank should have them. If you want to see variety in tank comps, differences between tanks should feel situational nice to have, without feeling essential.