Is 3DES still feasible (in terms of security and performance) to use?
3DES is very slow except if you have specialised hardware, so it at most wins in speed on legacy hardware that has dedicated DES circuitry but no AES circuitry. If no specialised hardware is available, AES or most other modern lightweight ciphers will be significantly faster.
3DES also has a very small block size, meaning it can start leaking data after just a few GB of encrypted data, see also Sweet32. Additionally the 112-bit key is considered to be quite short these days even though technically still sufficient, but it could be too short for e.g. reasonable security against multi-target attacks.
Is 3DES safe to use in ECB mode?
No block cipher is safe to be used in ECB mode, as you will always see which plaintext blocks appear multiple times. Additionally deterministic encryption (such as when ECB is used) cannot achieve security against chosen-plaintext attacks (a rather weak security notion).
Every time on giving the same input (plain text) to encrypt via 3DES
results same output (cipher text). What would the reason be for that?
For example: Every time I gave input plain text 'wealth' the output
generated was 'VxDfWEQA'. Or is that even possible?
(3)DES is a deterministic function, so if you give it the same input (that is the same message-key pair) twice you will get the same output twice. Randomness usually is only brought into the picture when using the block cipher. Also note that the probability of getting an ASCII-text ciphertext is $(52/256)^8\approx 0.000002898$.
If one would want to discourage a company to not to use 3DES with
cipher mode ECB and padding PKCS7 what would that reason would be and
See (1) and (3).
If a company/entity still insists to use 3DES. What configuration
would be the most suitable to be set for it e.g. cipher mode and
EAX or CCM mode or if neither are an option CTR mode with a counting (context-dependent) IV and then a secure message authentication code (MAC) applied on the ciphertext (which is what CCM and EAX do). These modes require no padding.