Helping refining a gish Cartographer artificer

Our table is about to start a Eberron-inspired steampunk campaign. I chose the new cartographer because I like teleporting and what better time to play artificer than in a steampunk world?

As part of our house rules, all players get a free feat, 1 uncommon item, and start at lvl 3. My DM and I came up with a fun home-brew version of the Gauntlets of Hill Giant Strength that has the properties of a greatclub, basically making Vi's gauntlets from Arcane. The limitations are that it's still treated like a two-handed greatclub, so no unarmed/monk shenanigans or holding a "second" weapon or shields. I'm fine with this, because I love the idea of "punching" people with booming blade/new true strike, then teleporting away.

Unlike other artificers, cartographers don't really have a use for their bonus action, especially with the new homunculus having no cost to control. So I'm thinking of taking Telepathic as my starter feat since I'm feeling that'll help even more with battlefield control and bamf-ing around the map. (And the +1 stat will get me to 20 INT).

My race is changeling for story reasons and so I can be a "living map", recreating charts and treasure maps as tattoos on my skin. (Plus the stat flexibility!)

I feel it's a good start, but I'm not sure exactly where to take it. At level four, I want to take the Spellfire Adept feat to boost radiant damage synergy with guiding bolt for range, 2024 True Strike for melee, and the Level 5 cart feature. And I'd like to get to take at least 6 levels of artificer to access to those next level infusions.

Our party has plenty of support with a cleric & bard already and plenty of ranged damage dealers, so I want to make a more offensive build focused on melee attacks & Gish spells. My only problem is that my STR w/o the gloves is an 8 and I had rough rolls for my starting hit points, plus no shield. But I'm hoping the teleportation can keep me out of harm's way?

All this makes me wonder if I should multi class into something like fighter or rogue (or heck, even warlock since I've got 14 CHA for changeling shenanigans). Action surge is always tempting as is picking up a fighting style, but rogues would also have a lot to offer. Probably not wizard though as we already have one.

Where should I take this? Should I consider a different starting feat beside telekinetic? Should I skip telekinetic and go straight for Great Weapon Master? (it will qualify for this home-brew weapon) And multi-classing? Are there other magic items/feats that synergies with radiant damage? I'm all ears.