I've just noticed this part:
allf100 wrote:/th/vs /d/
I am thirty.
Indian accent: I am dirty.
In a typical Indian accident the "th" sound would be pronounced as an aspirated dental stop (like Mandarin "t"!). It's definitely not voiced.
/r/ vs /l/
I agree.
Indian accent: I aglee.
No, Indian languages pretty universally differentiate /r/ and /l/, and sometimes even have retroflex counterparts of one or both. I would associate r/l confusion with Koreans and Japanese people, not South Asians.
/p/ vs /b/
It's time to sleep.
Indian accent: It's dime do sleeb.
Of the major Indian languages, I think only Tamil doesn't differentiate /p/ and /b/. /p/ has [b] as a variant in some positions, and /b/ can also occur in some affected speech in English and Indo-Aryan loanwords. What you're describing sounds more like a typical Arabic-speaker's accent.
The main difference from a typical Anglophone accent here would be that someone from an English-speaking country would probably pronounce the final p as unreleased in normal speech, while an Indian would pronounce it as a released (but still unaspirated) "p" sound.