I think it will work if you use lapply() at each step. This is the way to work with lists of things. The advantage of lists is that the things don't need to be the same type or shape.
files <- list.files(path = "documents", pattern = "csv$")
data <- lapply(files, read.csv)
data <- lapply(data, as.data.frame)
data <- lapply(data, t)
data <- lapply(data, dplyr::as_tibble, rownames = "X")