1) It's impossible to add an element <idle-timeout-minutes> to the model at all - in some cases it causes not known throwable during model marshalling, in other cases - operation fails;
2)element <set-tx-query-timeout> after parsing becomes an attribute of <time-out> element and I can't be loaded after re-parsing ;
3) it's impossible to add element <blocking-timeout-wait-millis> due to an error:
"failure-description" => "JBAS014677: Failed to persist configuration change: JBAS014675: Failed to marshal configuration",
4)there are some errors in adding <recover-credential>. When added this fragment:
operation.get("recovery-username").set("sa");
operation.get("recovery-password").set("sa");
operation.get("recovery-security-domain").set("HsqlDbRealm");
in XML it is:
<recover-credential>
<recover-credential>
sa
</recover-credential>
<recover-credential>
sa
</recover-credential>
<recover-credential>
HsqlDbRealm
</recover-credential>
</recover-credential>
5) It's impossilble to add attribute "enabled" to the root datasource element;
6) It's possible to add "track-statements" element set to "nowarn" to the model, but there is a problem to load the configuration after it, because of parsing error "there are not $TrackStatement.nowarn enum". On the other side it isn't possible to add this element set to "NOWARN".

When problems will be solver both tests must pass.