Re: Relation to sword?
Aikido is based on the sword in the respect that it was one of osensei's main arts. It would be correct to assume he incorporated parts of all his previous (japanese) arts to form a synthesis of sorts which he developed into the physical (aikido). But I also feel he included arts which he 'picked up' on his travels in China etc.
I was once told by Master Ma Boa Gao (hope the spellings ok), a Chinese chen style kung fu master that my 'kung fu was too big' - (I was demonstrating aikido at the time)?
I was invited to train with him and found, would you believe, 'small aikido'! There are obviously commonalities across all of the arts, but I was surprised at the great similarities between the two - especially the leading, dispersal of energy, flow, form and movements. The amazing ki/chi energy at the masters disposal was something else - I thought I was progressing after 25 -30years but it made me reassess my whole outlook on aikido. I hope I now flow a little better, but my Kung(aikido)fu is still too big??
The techniques translate well also.