The biggest issue about creating a character is that you're not only creating one character, but a piece in a 4 man team. This way, you need to think what kind of role will every character fill in a team.
Your build doesn't seem particularly bad, since it's a rogue that will focus on destroying a single target physical armor before applying CCs, comboing with necro, for that purpose. The problem I usually spot is trying to make some sort of hybrid build. There are 3 main stats (Str, Fin and Int) and 3 secondary stats (Con, Mem and Wit). What I recommend is picking one main stat which you'll try and always spend a point in, and splash between secondary stats, using Memory when needed and Wits to slightly increase Initiative.
Picking builds that deals damage both on Finesse and Int, as in your example, will make your character sub-optimal (in my opinion). You can still use a build like this (Scoundrel/Necro) but try and pick the necro spells that doesn't scale with Intelligence. This way, you can take advantage of Scoundrel's high damage (investing more in finesse) and still use the necro disables.
As for Sneaking or Thievery, I usually go for Thievery, since it usually has more uses (both lockpicking and pickpocketing). Now that backstab is a passive for daggers, rogues don't have a Talent Tax anymore, but I usually don't see myself sneaking while in battle, to be honest. So I'd change Guerilla for either The Pawn (1AP free for movement is great to position for backstabs or getting in rage, since scoundrel has low ranges) or Executioner (this would demand a point in Warfare, but since rogues usually last hit enemies, this generates a lot of AP). Keep in mind those two options are mutually exclusive.
Also, you didn't state your race. I believe, even after removing the Finesse bonus from EA, Elves are the best races to be rogues. They generate AP and gain bonus damage, while the Corpse Eater allows them to gain easy access to spells, specially on the early phases of the game. For example, you can gain Adrenaline pretty early on (you still need 1 Scoundrel and 1 Memory Slot to memorize it, but it's a free spell nonetheless).
Last edited by Zerd; 16/09/17 01:59 PM.