No worries; you are doing just fine.
No. Min-batches all contribute to the final model fit. Resampling methods fit separate models and these are only used to measure performance. Once resampling is finished, the individual models are discarded.
These is more that you can read in the feature engineering book and Tidy Models with R has a good illustration for V = 3

Yes, in my opinion.
Different resampling methods are statistical methods for estimating performance. Each has different properties. V-fold CV has better bias properties than the bootstrap. This means that the bootstrap is estimating something that may not be very close to the true, underlying performance value.
However, the variance of the bootstrap is very small (compared to V-fold CV). However, if the variance of CV is higher than you would like it to be, we can do repeats of CV to drive the variation down. The same approach does not help get rid of bias.
This blog post is a bit long but helps explain the difference.