Dunsdon v Dunsdon 2012 BCSC 1274 has an excellent and brief summary of the law relating to the removal of an executor-trustee, pre WESA as of April 1, 2014 :

[202] Put broadly, a trustee may be removed where his or her acts or omissions endanger the trust property or demonstrate a want of honesty, of reasonable fidelity, or of the proper capacity to execute the duties of office: Conroy v. Stokes [1952] 4 D.L.R. 124 (B.C.C.A.). The existence of friction between the trustee and one or more beneficiaries is usually not sufficient, of itself, to justify removal of the trustee: Erlichman v. Erlichman, 2000 BCSC 173; Re Blitz Estate, 2000 BCSC 1596. However, where there is dissension among the trustees themselves by which the trust administration grinds to a standstill or otherwise hampers the proper administration, the courts tend to remove one or more of them. In those instances, misconduct per se is not an essential prerequisite: Re Consiglio Trusts (No. 1) (1973), 36 D.L.R. (3d) 658 (Ont. C.A.); Wilson v. Heathcote, 2009 BCSC 554.

[203] In all cases, the fundamental guide must be the welfare of the beneficiaries: Letterstedt v. Broers (1884), 9 App. Cas. 371 (South Africa P.C.).