Help with itinerary.....another one!

@lifesupport

I think I'll take it easy and skip Madurai.
I have to decide if going to Kodaikanal following David'suggestion or going directly to Trivandrum.

If you visit Munnar you can skip Kodiakanal and vice versa (almost same hill station experience), moreover add Madurai and Rameswaram.

If you go to Kodaikanal, and visit the Greenlands Youth Hostel there (right by Coaker's Walk) you'll find a trekking guide who takes groups of tourists on a 2 day trekking trip through the forests to Munnar, using car and bus transport for parts of the journey. I wish I remembered the name.

My suggestion allows a Madurai stopover,

Pondi > Trichy > Madurai > Kumily (Thekady) > Munnar > Kochi (Fort Cochin) > Flight to Mumbai.

Some great scenery on the road journey Madurai > Theni > Kumily > Munnar.

Thanks to all of you.
Now I'm getting more confused.
I'm intrigued about Rameswaram but it seems far away from Kodaikanal and in general from Trivandrum-Kerala.

@lifesupport
My initial idea was to explore Kerala and add Gokarna or Goa. That is my priority. By the end of this month I want to be in Kerala in Trivandrum or Cochin so I have to figure out what I can visit in my first 10 days.

@mweupe

My initial idea was to explore Kerala and add Gokarna or Goa. That is my priority. By the end of this month I want to be in Kerala in Trivandrum or Cochin so I have to figure out what I can visit in my first 10 days.

Well, even your priorities should apply to the ten days.

Given your interests / preferences, with 10 days in hand (and from Pondy) you could reasonably visit:

Mysore and Hampi.

It will be a small chore getting to Mysore; the better option would be to get back to Chennai by any means, and then a train to Mysore.
https://erail.in/trains-between-stations/chennai-central-MAS/mysore-jn-MYS

A few days there and then the overnight train to Hospet (for Hampi) -
https://erail.in/trains-between-stations/mysore-jn-MYS/hosapete-jn-HPT

And then the overnight train to BLR
https://erail.in/trains-between-stations/hosapete-jn-HPT/ksr-bengaluru-SBC

and flight to TRV or COK;

or - with a view to the pennies - the overnight train from Bangalore to Thiruvananthapuram Pettah.
https://erail.in/trains-between-stations/ksr-bengaluru-SBC/trivandrum-pettah-TVP

In terms of visitor appeal, that would be my choice - I really enjoy both places.
https://www.lonelyplanet.com/india/karnataka/mysore
https://www.lonelyplanet.com/india/karnataka/hampi

Based on what you said about temples vs people, I'm unconvinced that the other 'obvious' destinations, say Tranquebar / Tanjore / Madurai will be of sufficient interst to you.

Your preference is magnified when you find yourself in "temple central" - Tamil Nadu.

https://www.lonelyplanet.com/india/tharangambadi-tranquebar
https://www.lonelyplanet.com/india/tamil-nadu/thanjavur-tanjore
https://www.lonelyplanet.com/india/tamil-nadu/madurai

As I indicated above, I wouldn't visit both Kodiakanal and Munnar, I'd choose one; better to arrive in Kerala (by whatever means) and visit Munnar. The town itself is none too appealing, but the countryside around certainly is.

@lifesupport

In ten days? I like the idea to visit Hampi and Mysore but what a journey.
I'm going to an agency to find out about trains. Thank you

Again with another question.
I'm in Varkala now and I have flight from Kochi on 29th March.

Planning to visit backwaters and Kochi but I think I have enough time to visit Kodaikanal instead of Munnar.

My question is how to reach Kodaikanal and best place to start the journey: Varkala, Aleppey or Kochi
Ideally it would be better from Kochi so to plan the days before the flight.
I searched for information but not clear if the only option is to go back to Madurai.

Thanks.

Planning to visit backwaters and Kochi but I think I have enough time to visit Kodaikanal instead of Munnar.

Why do you prefer Kodaikanal over Munnar?

My question is how to reach Kodaikanal and best place to start the journey: Varkala, Aleppey or Kochi

It makes little difference where you start. The best option is to take a car+driver, but I am aware you are trying to avoid those costs. As you are in country, you should approach a local travel agent, who has direct access to bus routes and other current local information.

https://www.redbus.in/search?fromCityName=Cochin&toCityName=Kodaikanal&fromCityId=216&toCityId=227&busType=Any&opId=0&onward=13-Mar-2019

Alternatively you could:

Take a train from Alwaye to Palani.
https://erail.in/trains-between-stations/aluva-(alwaye)-AWY/palani-PLNI
And from Palini take a car to Kodaikanal.

Varkala to Kodaikanal can be done by train. Taking anywhere from 6-10 hours depending which train. For some trains you may need to travel to Trivandrum. See a travel agent there to book the ticket.