If you have "spritz", which is carbon dioxide gas, then you have fermentation. No need for concern. Ginger beer often will not have the yeast krausen layer on top, the yeast remains suspended within the beer itself until it is finished and then will settle out.
All you need now is patience. Just leave it alone. All is well.
Cheers, good luck, ...
Yes, if you are using wine yeast it is common for a ferment to finish in a week. I've had commercial sized batches of grapes (multiple tons) finish in 7 days depending on how hot it is and the type of yeast.
The sulfur smell may or may not dissipate with time. I would rack off the yeast soon as that can sometimes contribute to hydrogen sulfide production.