Concerning the expectation matchers, there is a series of rewrite rules on the class side of PhexMatcher. This screencast explains how to use RB s rewrite engine: Code Critics in OB (OB Screencast 3).

First use these rules

RBParseTreeRewriter new
    replace:  self assert: [ `@expression ]  with:  self assert: `@expression ;
    replace:  self deny: `@expression  with:  self assert: `@expression not ;
    yourself.

Then use these rules

RBParseTreeRewriter new
    replace:  self assert: `@value = `@expected  with:  `@value should = `@expected ;
    replace:  self assert: `@value ~= `@expected  with:  `@value should not = `@expected ;
    replace:  self assert: `@value > `@expected  with:  `@value should > `@expected ;
    replace:  self assert: `@value < `@expected  with:  `@value should < `@expected ;
    replace:  self assert: `@value >= `@expected  with:  `@value should >= `@expected ;
    replace:  self assert: `@value <= `@expected  with:  `@value should <= `@expected ;
    replace:  self assert: (`@value isKindOf: `@type)  with:  `@value should beKindOf: `@type ;
    replace:  self assert: `@expression isNil  with:  `@expression should be isNil ;
    replace:  self assert: `@expression notNil  with:  `@expression should be notNil ;
    replace:  self assert: `@expression `test not  with:  `@expression should not be `test 
        when: [:node | node arguments first receiver selector matchesRegex:  (is|has|not).+|atEnd  ];
    replace:  self assert: `@expression `test  with:  `@expression should be `test 
        when: [:node | node arguments first selector matchesRegex:  (is|has|not).+|atEnd  ];
    replace:  self assert: (`@collection includes: `@element) not  with:  `@collection should not be includes: `@element ;
    replace:  self assert: (`@collection includes: `@element)  with:  `@collection should be includes: `@element ;
    yourself.

Concerning the introduction of dependencies between test, you have to rewrite your tests by Hand. For JExample there is JUnit2JExample but alas there is not automagic migration for Smalltalk (yet).

PS: if you are using the latest Pharo image you must use OB and revert the OB-Refactory package to get scoped rewrite rules working. Just execute

SystemBrowser default: OBSystemBrowserAdaptor.
Gofer new
    wiresong:  ob ;
    addPackage:  OB-Refactory ;
    revert