Your question is Is there anything wrong with this idea?, which I find hard to answer both because wrong is a relative term, and because it's not entirely clear to me what you want to accomplish, which would help with establishing a rough cost-benefit analysis.
So please forgive me for offering unordered thoughts:
It is unclear to me whether you are thinking about diverting your salary from your personal bank account to your LLC bank account, or you're thinking about asking your current employer to just send your salary to your LLC bank account. I believe the latter is unfeasible, because your employer cannot send money to another entity, and you're an employee, not an independent contractor (even setting aside for a moment what your HR reaction might be).
If, instead, you want to receive your salary in your personal bank account, and then transfer it to your LLC, you can - this can be done either as your personal loan to the business or an equity contribution.
A contribution to an LLC taxed as a disregarded entity has no tax consequences because the entity is not considered an entity separate from its owner. If it's a partnership or filing as a corporation, I believe that there are tax implications which you might find unfavorable.
It seems to be implied that the LLC is doing some kind of activity which is currently unprofitable; one would assume that this activity has nothing to do with the work you're doing for your employer. Keep in mind that some employers have very strict rules about moonlighting. In any case, you're alerting your employer that you have a LLC and a side activity, which might be undesirable.
If you transfer money into your LLC and then use your LLC for your daily expenses, you might be piercing the corporate veil. "Piercing the corporate veil" refers to a situation in which courts put aside limited liability and hold a corporation's shareholders or directors personally liable for the corporation’s actions or debts.
(Paying yourself a salary is a legitimate business purpose and does not constitute commingling of funds; but then, why don't you keep the salary from your employer to yourself in the first place?)
Assuming you're using credit cards for your expenses, you will probably stop building your credit (although you might build credit for your LLC).
Overall, it's not very clear what you want to accomplish and what the advantages would be for you. You mention:
- potentially keep some as savings for the LLC for future growth
But there's no need for this convoluted solution: just save money as an individual, and transfer these savings your LLC, as an equity contribution.
- use to pay myself for daily expenses, rent, etc.
Assuming that you're somehow neutral and you don't incur any expenses or taxes when transferring first to your LLC, and then back to yourself, what's the benefit here?
This might be an XY problem, and you might want to accomplish something that is not clear here, and with maybe a different solution.