Any ideas on what to do with my 5th level Rogue?

[Degwerks]

We're playing in Decent to Avernus right now and I have a 5th level High Elf Rogue "The Revived" subclass. We roll for stats and after my ability improvement at 4th I have 20 Dex, 16 Con/Wis, 13 Int, 9 Str and 12 Cha. I'm armed with a Silver Rapier and have a longbow that I do have some silver arrows for. I took Booming Blade for my high elf cantrip.

I've came up with the idea of changing my name every long rest, along with skill/tool prof. from Revived, to RP the past lives I've had. Now along with that, I'm thinking of grabbing additional classes for fun RP flavor, but not sure if that's going to make me less or more effective in combat. Thought about grabbing a couple Artificer levels to make my weapons magical and have a little emergency spells for healing or mitigating damage. Also thinking of Spare the Dying cantrip & Mending to repair my arrows, can't think that we will be finding a general store around to purchase supplies. Maybe splash in cleric/druid/ranger? It doesn't look like I really need stat bumps from ASI's so maybe a feat?

I'm looking for thoughts from people who've played a rogue in this campaign or someone who's played a Rogue in a campaign where monsters were resistant to non-magical damage. Right now I'm doing a lot of Bolts of the Grave, then readying my action on another players turn to get another sneak attack with my rapier or longbow.

All books & UA that is in D&D Beyond are allowed, also UA Class options too.

Any thoughts on this?
Current party is a straight ranged Champion Wood Elf Fighter; Warforged Veng. Paladin; 1/2 Elf Pala 2 / 3 Lore Bard; Psychic Sorc 3/ 2 Celestial Lock
Right now everyone can heal themselves a bit, if you count Fighter's 2nd Wind, but I cannot.

[RogueJK]

You most likely don't want to dilute your Rogue levels. However, a 1-2 level dip could be potentially handy.

Considering Avernus runs through level 12-13ish, look at the 11/12/13th level Rogue class and subclass abilities and determine if you can live with missing out on those upper level abilities in exchange for some lower level abilities from anther class.

For example, 2 levels of Ranger, which gets you an additional skill proficiency, Favored Enemy: Fiend, a little spellcasting, and the Dueling or Defense Fighting Style. And since UA is allowed, the UA Revised Ranger is a definite upgrade to the PHB Ranger.

[carrdrivesyou]

I have an AT rogue in Avernus right now. Gotta say, dipping a class before 10th would be a mistake. You will need that sneak attack progression to stay relevant in the fights. Remember, everything down here is stacked on HP and AC, so keep that in mind when leveling up.

My personal suggestion if you want to take some dips: Grab a trio of artificer levels after getting 10 rogue. Gives you a good way to gear up for late campaign critters, and fill holes in gear. So end result looks like Rogue 10/Artificer 3. I would suggest going Artillerist for your particular build and stats, as the temp hp turret on your shoulder will help shore up your low hp pool.