meaning - 少しぐらいは and 少しぐらい usage in casual speech

Could you please help me out with the last bit of this sentence:

「ええ。弓道部は問題児も多いし、巧いのが一人減ったからね。四月の新入生獲得の為に、少しぐらいは見栄えを良くしとかないと」

I've been wondering about the last bit, namely the usage of 少しぐらい and negative ending + と.

One definition of 少しぐらい that I found was 規模が不十分であることを示す表現, i.e. an expression to demonstrate an insufficiency in scope (please correct me if I'm wrong).

So if 少しぐらいは is the subject (I may be wrong here, as I've seen adverbs + は before but haven't seen grammar rules about it yet), then じておく (negative) + と - does it work like じゃん (isn't it)? Anyhow, does 少しぐらい add a negative (as in "we don't have enough!") or a somewhat positive implication ("little by little") in this kind of casual speech? That is, I'm not sure if she's complaining or being more positive.

Sorry if this sounds a bit confused.

Thank you for your patience.

Answer

少しぐらいは

少しぐらい（少しくらい） usually conveys a nuance like "wouldn't matter (to subject) with just a bit", that means the speaker is inclined to it.

少しぐらい分けてくれてもいいのに。 (implies they refuse to share a slightest bit to the speaker)

少しぐらい遊ぼうか。 (implies they couldn't play for some reason while they've longed to)

With this sense, 少しぐらい is adverb and rarely stands as a noun, so it's impossible to interpret it as a subject (the underlying form isn't 少しぐらいが). The real subject of this sentence should be "we" or "you" (but I can't decide from your context). The は is practically emphasizing the limitation, say, "compared to nothing".

A general tip is that you can't expect a subject should be manifested (or even some priority is given to) in Japanese, since the subject is one of the most inferable part unless you drastically change the topic.

しとかないと

It consists of "Verb + ておく (contracted) + ない + と". The last と is not "quotation" one but "conditional".

This part roughly means "must keep V-en (have V-ing done beforehand)". How come it means must? Actually, Japanese lacks a word must and we usually combine three elements (negation) + (conditional) + (word means "no good") to express "must / have to / have ~ to do" kind of meanings. The last part is often omitted in conversation, thus when you see a sentence ending in (negation) + (conditional), you can take it as a must with 95% confidence.

学校に行かなきゃ。
もう起きなければ。

買い物しないと。
生きねば。

Conclusion

少しぐらいは見栄えを良くしとかないと
lit. "We(?) must improve the appearance beforehand however little it differs (because I think it's good)."
→ I think we ought to make there looks a bit neater, at least better than nothing.

(Sorry if my English translation is awkward.)