This is interesting. As one who has gone to many different denominational churches throughout my life, I can't say that I've ever heard a sermon on tithing as a requirement for membership - EVER. In fact, the most powerful sermon I think I heard with respect to giving was a sermon on different types of giving that this pastor believed was giving (tithing) in the spirit of Christ. I remember examples of giving included helping someone on the street with extra change, helping a co-worker, friend or family member with a bill, giving time in terms of volunteer work to a charity group. That day, I ripped up my $20.00 check (which is my standard) and re-wrote a check for much more.
I sincerely do not remember EVER hearing a sermon that even suggested that my failure to tithe would banish me to Hades. Correlatively, never do I remember anyone being admonished for failing to give a certain amount of money to the church. Heck, if you don't have it? You don't have it! Conversely, I have heard countless stories of the church providing for people who were in need.
Given the pressure to perform and the comparisons in performance (titles and all), I would NEVER use my credit card for KH, assembly or convention activities.
This makes me wanna show up to a random KH and write a big fat check (so they have my address) after a service and drop it in the donation box. If called and asked about it, I'd say, that's my standard weekly donation. I wonder if I'd be able to get an elder to return and answer some darn questions after THAT! LOL LOL LOL