Yes, Deception is trash tier. Stab is such a bad version of Ram too, not only because it has a tendancy to miss half of the time if the enemy even blinks, but Ram can hit multiple enemies way easier and does around the same damage. Shift doesn't even seem to increase the damage at all. It's just there to let you backstab or get off a free two-handed jumping attack. At 2/3 later enemies can see right through it, so you need it to be 3/3, which is 21 FTH and not worth it if you're trying to be a "Rogue" like character.
AGI = Solace
STR/FTH = Brawler
If you decide to play NG+ Deception might be worth using for Mimic alone (it's great when you can actually see what's going on).
Yes. At the beginning at least, and if you are actually trying to remain a lithe, lightly armored character. There's nothing stopping you from donning heavier armor you can find early on, but what you end up with is a "Warrior" with much less burst, who can land backstabs somewhat easier and can riposte (which kind of doesn't matter since there's only one early enemy you can reliably riposte quicker than just backstabbing anyway).
At around level 30 - 35 the Rogue catches up in power, but for really stupid reasons and you also have to have advanced knowledge of the items, spell schools, scaling and weight limitations. So really, if you want more of a "challenge" at the start, pick Rogue. If you want to play a character that actually feels much more like something from any Souls game, pick Warrior and have fun smashing shit with jumping attacks.
You said you didn't want any advice really, but I'm going to tell you this much: save yourself a lot of trouble and pick either of the spell schools that are not Deception (you know, the most "Roguelike" school...). It only has one redeeming thing, and even that is not enough to use it over either of the other two.