Re: Training TKD/Karate while taking aikido?
My thoughts as someone with nearly 20 years of training karate and aikido.
I started with karate some years before aikido, so I wasn't trying to learn two arts from scratch.
The ryuha I trained in (primarily shotokan, but I was doing shito ryu at the time I started aikido) are so very different from aikido at the base level that it was impossible to get techniques mixed up.
FWIW, there are a few ryuha with aikido-type movement (Motobu-ryu is said to be so, Shindo Jinen Ryu was influenced by Ueshiba) and these may be even more complimentary to aikido.
To the original poster, shorei sounds like an Okinawan system, and may therefore teach (so some extent) Ryukyuan kobudo as well.
Hope this helps.