Here is Saturday's plan - (my original idea was for trains either end but the bus replacements actually look more convenient)

From Exeter --buy return train ticket to Feniton St Davids 10.23 (Central 10.28) Catch bus replacement to Whimple . Arrives 10.59 (Buses are every hour so you could catch up if you came on next one)

From Honiton -- buy return train ticket to Whimple Honiton station catch 10.47 bus replacement to Whimple . Arrives 11.22 (Buses every hour)

First pub -- New Fountain Inn (opens at 11.00). Possibly check the Thirsty Farmer.

Leave Whimple by 12.30pm at the latest and walk (about one hour by little roads) to Talaton. Talaton Inn open 12.00 - 3.00

Leave Talaton by 2.15 at the latest and walk ( about 45 mins by little roads) to Feniton Nog Inn open from 1.00 - 4.00pm on Saturdays

Return to Exeter or Honiton
Bus replacements from Feniton to Exeter at 3.02pm, 4.02pm or 5.02pm
Bus replacements from Feniton to Honiton at 3.14pm, 4.14pm or 5.14pm

You may wish to eat at one of the first pubs or bring your own food.