Although I don't pretend to be a lawyer - cos I'm not

I have read most of it a few times and each time the following seems to be true and correct.
If a registrar is accredited by ICANN then they have agreed to the terms and conditions set by ICANN.
This being one of them - (from the link you posted above.)
3. REGISTRAR OBLIGATIONS.
3.7.9 Registrar shall abide by any ICANN adopted specifications or policies prohibiting or restricting
warehousing of or speculation in domain names by registrars.
This article is a recent discussion about registrars Tasting domains for profit (speculating)
- 6 march 2008
http://gnso.icann.org/mailing-lists/archives/registrars/msg05701.html
The above restriction on use of the Add Grace Period shall be
considered an "ICANN adopted specification or polic[y]
prohibiting
or restricting warehousing of or speculation in domain names by
registrars" in accordance with Section 3.7.9 of the Registrar
Accreditation Agreement. As such, a Registrar that engages in
domain tasting,
defined as using the AGP to register domain names in
order to test their profitability, shall be deemed in material
breach of the Registrar Accreditation Agreement.
The amendment succeed.
In favour: Philip Sheppard, Bilal Beiram, Kristina Rosette, Cyril Chua,
Tony Holmes, Tony Harris, Greg Ruth, Robin Gross, Carlos Souza, Olga
Cavalli, Avri Doria (one vote each)
Tom Keller, Adrian Kinderis, Tim Ruiz, Chuck Gomes, Edmon Chung, Jordi
Iparraguirre (two votes each)
Opposed: Mike Rodenbaugh (1 vote)
So, an ICANN accredited registrar is not allowed to make money by speculating (which they do if the hold or auction the names and split the profits) - They are not allowed to own a large number of domains (warehousing) and they are not allowed to taste domains for traffic.