What about bash one liners?
I had a bad experience with Ubuntu's (Debian's) dash shell many years ago and I've (lazily) just stuck with bash since then.
For me, yes I still write my scripts in hashbanged (ba)sh scripts; the only fish I write is my config.fish. Fish might be an objectively better language, I don't want to learn it and prefer keeping writing (ba)sh, as
1. (ba)sh is an evil I know...
2. ... that I must know anyway to work on servers (while fish's "utility" is low as used nowhere but around the fish shell)...
3. ... and shellcheck makes it (a bit) less of a footgun.
When I do need to write a bash one-liner, I just run it in bash :) . But it's a once-in-a-blue-moon occurrence, since pipes are the same, and fish added syntax for && and || a few years ago (before that, they didn't exist and you had to use and; and or;), and added support a few months ago for `FOO=bar ...` direct env.var setting (before that you had to `env FOO bar ...`). So, your typical `thing --blah | grep stuff | awk stuff | whatever && something` generally works in fish.
* do you have any trouble running shell scripts?
Nope. fish will run bash for most shebangs.
* What about bash one liners?
You will have to translate these.
You can still type "bash" to get bash.