Looks like a solid Party. Is the priest a decent character? Seems to me the bishop and valk can handle your healing needs till the Gadgeteer and Bard get stamina heal. What do you have against stealth?
I mentioned it in another thread; the Priest is more like a differently balanced hybrid. Having a Priest lets you get Armorplate early, and later on a Priest with a good weapon and Power Strike can be a decent attacker while still getting pure caster progression. Just remember that a front line priest will wand a shield.
Also, one of the few class changes that actually works IMO is to start as a Priest to learn the important spells and then change to Valkyrie/Lord; essentially you delay the 4 levels where your spellcasting doesn't progress.
One other thing of note about Priests is that, at level 24+, Priests are the only class that can cast Restoration or Death Wish at power level 7 with no chance of failure.
The problem with Stealth is that it makes the character with the skill less likely to be targeted and can't be turned off. In a party, this means that enemies are more likely to attack your vulnerable spellcasters than your hgh AC Rogue. In a solo (which isn't my thing, by the way), high Stealth makes it so that enemies stop attacking you and just defend, and that's no fun.