Hi Eyebuck
Regarding tactics for playing Vior'la, my basic advice comes in two versions.
If you are used to playing other Epic armies, you need to play more defensively, patiently, and from longer ranges than you might be used to. You need to wait for the enemy to come to you, then set up crossfires ideally with markerlit support.
If you are used to playing other Tau armies, you can play more aggressively, and can tackle them at 45cm instead of extreme ranges. You can advance more than you are used to, then set up crossfires ideally with markerlit support.

The point of those almost contradictory statements is to illustrate that Vior'la are an aggressive, midfield-orientated army
compared to third phase Tau, but still have to be played cautiously compared to most other Epic forces.
That advice applies to Riptides. They can take a punch better than most Tau units, and do all their work at 45cm, but are still non-fearless and prefer to minimise assaults.
Rather than thinking of them as scaled-down warhounds, it's better to see them as scaled-up Crisis Suits. Where a warhound will commonly fire everything turn 1, then assault with support on turn 2 and trust its void shields to help towards a victorious combat resolution or its fearlessness to keep it from harm in a loss, Riptides almost always want to be used as a firing weapon. They do however have similar armour to Crisis Suits and benefit from the Tau Jet pack rule (units with Tau Jet Packs are allowed to make an additional move of 10cm at the end of an advance, double or march order) which is really handy for keeping them a little further from the enemy or, if you plan right, allowing them to get back into terrain.
Regarding the commander being in a Riptide suit, it's a good choice (better than having him off the table in an Orca!) but you need to be aware of the specific weaknesses of warengines to things like Death Strikes and long range TK (he mustn't be the front model) and in particular Pinpoint attacks that can pick any WE model. If the opponent has a space ship, I suggest putting him in terrain and having the rest of them outside it. They shoot at -1 or they pick someone who isn't your SC. They'll probably pick the SC anyway, but every little bit of advantage helps.
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I do this because all of my xv8s are being airdropped by orcas later in game and I don't want to mis out ony commander re-roll.
If you're running low on tetras (ie, the opponent has sneezed in their direction), try have the Riptides somewhere you they will grant crossfire to your Xv8s on arrival.
If you use 2 formations of Riptides, try keep them about 45cm from each other as they move up field, and zap anything that is in between them.
I hope that's a start towards your planning, but feel free to ask if you have any questions.
Good luck!
Matt