I haven't worked in CAH billing which I know has some special rules, but I can tell you how this has been handled in the facilities where I've worked.
The lithotripsy information you describe sounds correct to me - the laser is part of the equipment used in the surgical procedure in the OR so I agree that this would be part of the OR charges reported under revenue code 360 with the CPT procedure code that matches the procedure documented by the surgeon, and that it how I've seen in done. (The exception would be if the lithotripsy was an ESWL, CPT 50590, then it would be billed with revenue code 790 instead of 360.)
PICC line placements are also surgical procedures so your reporting should be similar, though if they're not done in the OR then you might not use a different revenue code than 360. I've seen this billed with revenue code 361 for a minor procedure or 761 for special procedure room, or even 450 or 459 if the line was placed in the ED. You would be reporting the appropriate CPT code from the range 36568-36573 for this.
Revenue code 270 would an unusual way to report these because that is for miscellaneous supplies, but I don't know that it will really make a difference because the revenue code reports the cost center associated with those expenses and ultimately is not going to affect reimbursement, which is tied to the CPT/HCPCS codes, not the revenue codes, for most payers. You may want to review the UB manual for guidance on the appropriate use of the revenue codes and compatibility of revenue codes with specific CPT/HCPCS codes.
When you say this company puts in and removes the PICC lines, are you paying this company for the physician service involved in these procedures and if so, are you billing a professional claim to recover those costs?