I've been doing the Blu Classic tobacco disposable e-cigs for a while but decided to try a refillable option. And wanted different favors. But I wanted something that wasn't so bulky as many of these tanks and batteries seem huge compared to what I'm used to.

Just hit a local shop and ended up with the Aspire K3 quick start kit. How are those?

For the juice, I got Cream of the Crop "creamy sweet tobacco". Don't really care for it though. Found out after I purchased it's a tobacco-free nicotine. Synthetic? Is it safe and been around for a while?

What's a decent tobacco flavored juice I can try?

Your probably not going to find the "perfect" tobacco flavor out there.  There is really nothing that tastes like a normal cig.  A lot of people like the RY4 flavor, and these guys are good to go when it comes to that.  They do have other "tobacco" flavors on their site as well.

Mountain Oak

When I started vaping I stayed away from the tobacco flavors as wanted to get away from tobacco. Now days I just mix my own as it is cheaper. And I do have the big bulky heavy mod with big tank on it for subohm coils. And yes RY4 is really the go to for tobacco flavor.

Agreed, most straight tobacco flavors are nasty. A good VCT- Vanilla Custard Tobacco is recommended. The best I have tried: https://ripevapes.com/product/vct/#

Alloy Blends Vented - favorite vanilla tobacco
High Roller Suites Roulette - another good sweet tobacco

Most tobacco flavors suck - these don"t

giantvapes.com is where i get my vented, order a 120 - you will wish you did if you only get a 30ml