To answer questions in sequence:
1. I guess you can substitute xylene with  any clearing agent.......have
never tried it
2. the peanut oil (or clove or groundnut) reduces the aggressiveness of the
clearing agent and tries to conserve the fragile fatty capsule. The fatty
capsule influences the penetration and removal of the stain. M Leprae is
much less acid/alcohol fast and therefore avoidance of defatting
agents/solvents is necessary.
3. The Wade Fite method calls for 5% sulphuric acid in the differentiation
step........having never had the problem of not having sulphuric acid, I
can't say what you can substitute.
4. Why not try it? Get a good positive control and substitute your xylene
with histoclear and sulphuric acid with aqueous HCl.
5. Would be interested in your findings.

Evelyn Kaplan
Dept of Pathology,
Sultan Qaboos University,
Muscat, Oman