loubikes

My back rim accepts a schrader stem but I've been using tubes with presta stems.

I know some say that the stem can get ripped off when the tube slides. Is this true? I'm planning a week-long tour and I'm wondering if I should address this before I go.

I bought the bike used and it came with two different rims.

What is the easiest/cheapest solution? Get a tube with a schrader stem and get a bike pump that can handle both?

I haven't had to buy/shop for tubes for this bike yet. Do most 700 x 28c-32c tubes tend to come with a certain stem (schrader/presta) or can you get either?

Thanks