where your counter top meets the back splash, there should not be any grout, just caulk (you can buy it in colors to match your grout). The grout in that joint will crack.

What about the weird caulking that seems to be a bit like my grout?

The wierd caulking that seems a bit like your grout should be all you need (siliconized latex).

However, for the benefit of those who might come across this thread on a search, if there's grout in that joint where the backsplash meets the countertop, that grout needs to be raked out before it gets caulked If you caulk over the grout, it'll just peel back out pretty quickly. It needs to be able to anchor itself in the joint.

Bathroom was just remodeled & hairline cracks appear where tub meets floor; contractor's solution was to put silicone over the grout; do you think we will have water damage ?

Have him remove the grout then silicone. Maintain it and you'll have no water damage.

Silicone is best when left unopened, 20ft. deep in a landfill.

POLYSEAMSEAL, however, remain flexible for 20yrs. tools with your dampened finger, can be painted, is available in many colors and if you are good can be mixed for color matches.

lorettarigg

If the silicone way applied and correctly tooled so that it lapped onto both the tub and flooring material, and was allowed to cure properly it should be ok, until it's not.

If you began to see staining behind the surface, don't put off corrective action.

Grout, when a vinyl add-mix is used, is water resistant.