Will a tvs diode help the relay with inductive loads

With the concerns you state, and especially with having the relay installed in a wall, I guess the answer is:

Don't.

You might add a fuse, but then, you'd have to find a rating in the relay's data sheet telling you if it is approved for usage with a fuse, and if so, what the fuse's rating would have to be. All in all, you would have to do the same qualification for the entire system (relay, fuse, type of outlet socket, possible loads) that the original vendor did for the combinaiton of the relay and fountain.

The relay will not limit the current (amps) to a level that is safe to itself. When overloaded, it will likely act like a short circuit for moderate overload conditions and will fail open (or explode, or burn) for severe or ongoing overload conditions.

The thing to remember is this: Once you exceed any of the ratings, the manufacturer won't guarantee anything they tell you in the data sheet any more and you are on your own.

Also, with having the relay installed in a wall where it can't really get rid of any heat it produces, I recommend using the derating curve for 60...70 °C, which tells you to rather not exceed 2...3 A.

A hacker's answer, however, is:

Yes, your setup might work, ...

... but you would have to make sure all is well and within the specified limits and characteristics.

According to the datasheet, the G3MB-202P is a discontinued zero-crossing switched AC SSR.

So, when it is commanded to turn on, it will delay by up to 1/2 of an AC cycle until the next zero crossing. So, at 50/60Hz it can delay by as much as 10msec or 8.33msec

When it is commanded to turn off, it cannot turn off until the current crosses zero. This can be as much as 10msec or 8.33 msec again, but not necessarily in phase with the voltage.

For a resistive load you if you commanded it on for a bit more than 10msec it would be guaranteed to turn on, and commanded it off for a bit more than 10msec it would be guaranteed to turn off. Using say 10.5 msec for each, that's 21msec or about 47Hz. In reality you would get beating between commands and response frequencies with wildly varying amounts of power, so perhaps 1/10 of that frequency or about 5 or 6Hz is more reasonable as a maximum, but even that is a bit high.

If you want to get 'even' and fairly-beat free power (for example for a PWM heater control), normally 0.5Hz is about right (gives you 200 half cycles per period at least).

Nothing you can do by commanding the relay will damage it with a simple load like lights, but you may get undesirable (or perhaps interesting) variations in light if you cycle it too fast. Some will probably appear as smooth pulsations in brightness, which might be quite okay. The life of the lights might be shortened a bit if they're incandescent, but they're only Christmas lights.