i guess that's how most church groups get started - they do not agree with the rules of the previous one.
sadly the case, but i do agree with how you see it.
i'm no longer a church person, but a long time ago, for a brief period of time, i was involved with the music ministry of my parent's
religious group (not a church), and my then bestbud's church (legit church). in both cases, i dressed up well, and went along
with the rules, which to me sounded acceptable. long hair was allowed, dress in a semi formal manner, no roughed up jeans,
no colored nails, no shirts marked with blasphemous messages. play what is required of you - that meant no distortion, no fancy leads,
no sudden outbursts of fancy bass playing, no david lee roth-showmanship. i think everyone wants to focus on the singing, and the
ministry itself - a lot of them would be impressed by your sweep + tap runs, but they would want to sing and do worship first.
which is why i'm quite impressed with how the cumc used to (do they still do this? please correct me) set aside a friday night for music ministry aimed at the
youth, everyone is free to come and join in. the rules are relaxed during these times, and everyone has a good time.
i would tend to suggest that for the purposes of praise and worship, it would be best to dress up well, formally if any. it's a church,
there's worship going on, people are often deep in thought and connection, i don't think they'd take well if you wore torn jeans and your
faded Iron Maiden shirt, playing on your insanely stickered guitar with a hundred pedal rig.
save that for secular gig nights / appearances.
if i was to join a church now, and wanted to serve in ministry, i'd go with the set rules.