Well, I have to admit, I'm in the whole "Clerics are necessary in the Classo" group, so long as you intend on ever doing any solo play at all. If you group ALL the time, then cleric is unnecessary - pretty much everyone else will have cleric in their classo, so it's fine if you don't.
It allows you to play interesting classo's that will have their own advantages, freeing up that spot usually used for cleric.
Furthermore, a Necro/Druid non-cleric classo isn't particularly disadvantaged as you get similar protective/healing spells through those two classes, which goes a long way to make up for the loss of the clerical spells.
Lack of Supplication is meaningless - to be honest, Animate Dead/Summon, the Druid's summoning spell both produce perfectly good - if not better - followers more reliably as you don't have to hold alignment for them, and can have more than one.
I can't remember what your classo is off hand (not online right now), but really, cleric's not so necessary overall.
Now, assuming you don't have Druid, Necromancer, OR cleric, you're going to be pretty much incapable of solo play, but you can still be a valuable contributer in groups, in different ways depending on your classo.
Really, whether a Classo is good or not depends mostly on what you want to do. A 4xcaster, for example, makes a piss poor tank simply because they cannot protect, even though they can be rediculously powerful in close combat.
As to your other points....
Clerics SHOULD have all the powerful healing spells, just like how mages should have the best blasting spells, necromancers should have the best undead-related spells, ect, ect. It's what clerics do.
Sanc/Aegis? Druids get Fluidity/Greater Fluidity, which perform a similar function (and stack with sanc-effects), Necromancers get Wall of Flesh which, while different in implementation, has the same overall effect as sanc. I can't tell you how many times I've wished I had Wall instead of Sanc, for those long chop fights, or the situation where there are several mobs all in the same room.
Raise dead? Well, it would be handy if more people had it, but unnecessary. Overall, most people will take cleric in their classo, so there'll always be lots of raisers about. Necros shouldn't get it as it's kinda antithetical to what they do, Druid's shouldn't because they have their own things they are good at. It's important to have the various classes have their own advantages and disadvantages, to make the multi-class system work.
Supplication? Why? Again, Necro animating/summoning is BETTER. Sure, your undead followers can't heal you, but you can always get them. Pretty much every cleric would happily trade Supplication for the necro variants. I know I personally would LOVE to be able to have multiple followers who I could summon regardless of my alignment. Try being Neutral as a cleric - no supp's at all!
Bards are VERY handy to have in groups - Once you've been around longer, particulalry around high level bards - you'll appreciate what they can do. I may not wish I had bard in my classo, but I certainly want them in my groups!
Warrior types, well, that's another kettle of fish entirely.
Don't get me started on that
