"Failing to pay traffic fines can lead to a block on obtaining driving and vehicle licences, in addition to an administrative fee – in addition to other penalties." - Probably wouldn't stand up to legal challenge. OUTA has already established that is not legal to withhold licenses on the basis of unresolved tolls, etc and fines would probably fall under this.
"Where documents previously had to be delivered by registered mail through the post office, in terms of the amendment, authorities will now also be able to serve documents via e-mail and to send reminders via WhatsApp and SMS." - They can deliver them however they want but there will be no way for them to prove that you received them like this so this would probably just fall over in a legal challenge.
"A controversial change to the bill is that the option for offenders to elect to appear in court to challenge the prosecution has been removed." - Unconstitutional, unless all traffic offences will now be considered purely civil issues. Definitely unconstitutional if any of these prosecutions can result in a criminal record without the right to appear in court to defend yourself.
"A new demerit system will be introduced. Depending on the severity of the offence, 1-6 points are allocated for offences. If an infringer has more than 12 points, it will result in the disqualification of the driving licence and three suspensions result in its cancellation." - I won't hold my breath. The famous demerit system has been perpetually imminent since about 1998.